diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,25 @@
 # dhall-to-cabal change log
 
+## 1.3.1.0 -- 2018-10-23
+
+* Allow `Cabal` version 2.4.0.0. There have been consequent changes to
+  the extensions, compilers and licenses recognised.
+
+* Allow `dhall` version 1.18.
+
+* `dhall-to-cabal` and `cabal-to-dhall` now understand the `mixins`
+  field properly.
+
+  On the Dhall side, `types.ModuleRenaming` has changed significantly:
+  it is now a union.
+
+  `prelude.types.ModuleRenaming` has been added for convenient access
+  to the new constructors.
+
+* Fix issue with alpha-normalized expressions. This was identified in issue #124
+  and fixed in issue #126.
+
+
 ## 1.3.0.1 -- 2018-08-10
 
 ### Distribution Changes
diff --git a/dhall-to-cabal.cabal b/dhall-to-cabal.cabal
--- a/dhall-to-cabal.cabal
+++ b/dhall-to-cabal.cabal
@@ -1,4 +1,4 @@
-cabal-version: 2.2
+cabal-version: 2.4
 -- * * * * * * * * * * * * WARNING * * * * * * * * * * * *
 -- This file has been AUTO-GENERATED by dhall-to-cabal.
 --
@@ -9,7 +9,7 @@
 -- 'dhall-to-cabal -- dhall-to-cabal.dhall > dhall-to-cabal.cabal'.
 -- * * * * * * * * * * * * WARNING * * * * * * * * * * * *
 name: dhall-to-cabal
-version: 1.3.0.1
+version: 1.3.1.0
 license: MIT
 license-file: LICENSE
 maintainer: ollie@ocharles.org.uk
@@ -129,14 +129,13 @@
                  -Wno-missing-local-signatures -Wno-monomorphism-restriction
                  -fno-warn-name-shadowing
     build-depends:
-        Cabal ^>=2.2,
+        Cabal ^>=2.4,
         base ^>=4.10 || ^>=4.11 || ^>=4.12,
         bytestring ^>=0.10,
         containers ^>=0.5 || ^>=0.6,
         contravariant ^>=1.4 || ^>=1.5,
-        dhall ^>=1.16.0,
+        dhall ^>=1.18.0,
         hashable ^>=1.2.6.1,
-        insert-ordered-containers ^>=0.2.1.0,
         text ^>=1.2,
         transformers ^>=0.5.2,
         vector ^>=0.12
@@ -156,12 +155,11 @@
                  -Wno-missing-local-signatures -Wno-monomorphism-restriction
                  -fno-warn-name-shadowing
     build-depends:
-        Cabal ^>=2.2,
+        Cabal ^>=2.4,
         base ^>=4.10 || ^>=4.11 || ^>=4.12,
-        dhall ^>=1.16.0,
+        dhall ^>=1.18.0,
         dhall-to-cabal -any,
         filepath ^>=1.4,
-        insert-ordered-containers ^>=0.2.1.0,
         microlens ^>=0.1.0.0 || ^>=0.2.0.0 || ^>=0.3.0.0 || ^>=0.4.0.0,
         optparse-applicative ^>=0.13.2 || ^>=0.14,
         prettyprinter ^>=1.2.0.1,
@@ -184,7 +182,7 @@
                  -fno-warn-name-shadowing
     build-depends:
         base ^>=4.10 || ^>=4.11 || ^>=4.12,
-        dhall ^>=1.16.0,
+        dhall ^>=1.18.0,
         bytestring ^>=0.10,
         dhall-to-cabal -any,
         optparse-applicative ^>=0.13.2 || ^>=0.14,
@@ -204,7 +202,7 @@
     build-depends:
         base ^>=4.10 || ^>=4.11 || ^>=4.12,
         directory ^>=1.3.0.2,
-        dhall ^>=1.16.0,
+        dhall ^>=1.18.0,
         dhall-to-cabal -any,
         filepath ^>=1.4,
         optparse-applicative ^>=0.13.2 || ^>=0.14,
@@ -222,15 +220,36 @@
                  -fno-warn-name-shadowing
     build-depends:
         base ^>=4.10 || ^>=4.11 || ^>=4.12,
-        Cabal ^>=2.2,
+        Cabal ^>=2.4,
         Diff ^>=0.3.4,
         bytestring ^>=0.10,
-        dhall ^>=1.16.0,
+        dhall ^>=1.18.0,
         dhall-to-cabal -any,
         filepath ^>=1.4,
         microlens ^>=0.1.0.0 || ^>=0.2.0.0 || ^>=0.3.0.0 || ^>=0.4.0.0,
         prettyprinter ^>=1.2.0.1,
         tasty ^>=0.11 || ^>=0.12 || ^>=1.0 || ^>=1.1,
         tasty-golden ^>=2.3,
+        text ^>=1.2
+
+test-suite unit-tests
+    type: exitcode-stdio-1.0
+    main-is: Tests.hs
+    hs-source-dirs: tests
+    other-modules:
+        DhallToCabal.Tests
+    default-language: Haskell2010
+    ghc-options: -Weverything -Wno-safe -Wno-unsafe
+                 -Wno-implicit-prelude -Wno-missed-specialisations
+                 -Wno-all-missed-specialisations -Wno-missing-import-lists
+                 -Wno-missing-local-signatures -Wno-monomorphism-restriction
+                 -fno-warn-name-shadowing
+    build-depends:
+        base ^>=4.10 || ^>=4.11 || ^>=4.12,
+        Cabal ^>=2.4,
+        dhall ^>=1.18.0,
+        dhall-to-cabal -any,
+        tasty ^>=0.11 || ^>=0.12 || ^>=1.0 || ^>=1.1,
+        tasty-hunit ^>=0.10.0.1,
         text ^>=1.2
 
diff --git a/dhall/defaults/CompilerOptions.dhall b/dhall/defaults/CompilerOptions.dhall
--- a/dhall/defaults/CompilerOptions.dhall
+++ b/dhall/defaults/CompilerOptions.dhall
@@ -1,7 +1,9 @@
 -- This file is auto-generated by dhall-to-cabal-meta. Look but don't touch (unless you want your edits to be over-written).
     let types = ./../types.dhall
 
-in  { GHC =
+in  { Eta =
+        [] : List Text
+    , GHC =
         [] : List Text
     , GHCJS =
         [] : List Text
diff --git a/dhall/prelude.dhall b/dhall/prelude.dhall
--- a/dhall/prelude.dhall
+++ b/dhall/prelude.dhall
@@ -15,6 +15,8 @@
         constructors ./types/SPDX/LicenseExceptionId.dhall
     , LicenseId =
         constructors ./types/SPDX/LicenseId.dhall
+    , ModuleRenaming =
+        constructors ./types/ModuleRenaming.dhall
     , TestTypes =
         constructors ./types/TestType.dhall
     , RepoType =
diff --git a/dhall/types/Arch.dhall b/dhall/types/Arch.dhall
--- a/dhall/types/Arch.dhall
+++ b/dhall/types/Arch.dhall
@@ -1,4 +1,6 @@
-< Alpha :
+< AArch64 :
+    {}
+| Alpha :
     {}
 | Arm :
     {}
diff --git a/dhall/types/Compiler.dhall b/dhall/types/Compiler.dhall
--- a/dhall/types/Compiler.dhall
+++ b/dhall/types/Compiler.dhall
@@ -1,4 +1,6 @@
-< GHC :
+< Eta :
+    {}
+| GHC :
     {}
 | GHCJS :
     {}
diff --git a/dhall/types/CompilerOptions.dhall b/dhall/types/CompilerOptions.dhall
--- a/dhall/types/CompilerOptions.dhall
+++ b/dhall/types/CompilerOptions.dhall
@@ -1,21 +1,23 @@
-{ GHC :
+{ Eta :
     List Text
+, GHC :
+    List Text
 , GHCJS :
     List Text
-, HBC :
+, NHC :
     List Text
-, Helium :
+, YHC :
     List Text
 , Hugs :
     List Text
+, HBC :
+    List Text
+, Helium :
+    List Text
 , JHC :
     List Text
 , LHC :
     List Text
-, NHC :
-    List Text
 , UHC :
-    List Text
-, YHC :
     List Text
 }
diff --git a/dhall/types/Extension.dhall b/dhall/types/Extension.dhall
--- a/dhall/types/Extension.dhall
+++ b/dhall/types/Extension.dhall
@@ -10,6 +10,8 @@
     Bool
 | BinaryLiterals :
     Bool
+| BlockArguments :
+    Bool
 | CApiFFI :
     Bool
 | CPP :
@@ -136,6 +138,8 @@
     Bool
 | NumDecimals :
     Bool
+| NumericUnderscores :
+    Bool
 | OverlappingInstances :
     Bool
 | OverloadedLabels :
@@ -164,6 +168,8 @@
     Bool
 | PostfixOperators :
     Bool
+| QuantifiedConstraints :
+    Bool
 | QuasiQuotes :
     Bool
 | Rank2Types :
@@ -193,6 +199,8 @@
 | ScopedTypeVariables :
     Bool
 | StandaloneDeriving :
+    Bool
+| StarIsType :
     Bool
 | StaticPointers :
     Bool
diff --git a/dhall/types/ModuleRenaming.dhall b/dhall/types/ModuleRenaming.dhall
--- a/dhall/types/ModuleRenaming.dhall
+++ b/dhall/types/ModuleRenaming.dhall
@@ -1,1 +1,7 @@
-List { rename : Text, to : Text }
+< renaming :
+    List { rename : Text, to : Text }
+| default :
+    {}
+| hiding :
+    List Text
+>
diff --git a/dhall/types/SPDX/LicenseExceptionId.dhall b/dhall/types/SPDX/LicenseExceptionId.dhall
--- a/dhall/types/SPDX/LicenseExceptionId.dhall
+++ b/dhall/types/SPDX/LicenseExceptionId.dhall
@@ -1,21 +1,21 @@
-< Autoconf_exception_2_0 :
+< DS389_exception :
     {}
+| Autoconf_exception_2_0 :
+    {}
 | Autoconf_exception_3_0 :
     {}
-| DS389_exception :
+| Bison_exception_2_2 :
     {}
 | Bootloader_exception :
     {}
 | Classpath_exception_2_0 :
     {}
-| Bison_exception_2_2 :
+| CLISP_exception_2_0 :
     {}
 | DigiRule_FOSS_exception :
     {}
 | ECos_exception_2_0 :
     {}
-| CLISP_exception_2_0 :
-    {}
 | Fawkes_Runtime_exception :
     {}
 | FLTK_exception :
@@ -24,27 +24,37 @@
     {}
 | Freertos_exception_2_0 :
     {}
+| GCC_exception_2_0 :
+    {}
 | GCC_exception_3_1 :
     {}
 | Gnu_javamail_exception :
     {}
-| GCC_exception_2_0 :
-    {}
 | I2p_gpl_java_exception :
     {}
 | Libtool_exception :
     {}
 | Linux_syscall_note :
     {}
+| LLVM_exception :
+    {}
 | LZMA_exception :
     {}
+| Mif_exception :
+    {}
 | Nokia_Qt_exception_1_1 :
     {}
 | OCCT_exception_1_0 :
     {}
-| Mif_exception :
+| OpenJDK_assembly_exception_1_0 :
     {}
 | Openvpn_openssl_exception :
+    {}
+| PS_or_PDF_font_exception_20170817 :
+    {}
+| Qt_GPL_exception_1_0 :
+    {}
+| Qt_LGPL_exception_1_1 :
     {}
 | Qwt_exception_1_0 :
     {}
diff --git a/dhall/types/SPDX/LicenseId.dhall b/dhall/types/SPDX/LicenseId.dhall
--- a/dhall/types/SPDX/LicenseId.dhall
+++ b/dhall/types/SPDX/LicenseId.dhall
@@ -22,80 +22,84 @@
     {}
 | Afmparse :
     {}
-| AGPL_3_0_only :
+| AGPL_1_0_only :
     {}
-| AGPL_3_0_or_later :
+| AGPL_1_0_or_later :
     {}
 | AGPL_1_0 :
     {}
-| AMDPLPA :
-    {}
-| AML :
+| AGPL_3_0_or_later :
     {}
 | Aladdin :
     {}
-| ANTLR_PD :
+| AGPL_3_0_only :
     {}
-| Apache_1_0 :
+| AML :
     {}
 | AMPAS :
     {}
-| Apache_1_1 :
+| AMDPLPA :
     {}
-| Apache_2_0 :
+| ANTLR_PD :
     {}
-| APL_1_0 :
+| Apache_1_0 :
     {}
-| APSL_1_0 :
+| Apache_2_0 :
     {}
 | APAFML :
     {}
+| Apache_1_1 :
+    {}
+| APSL_1_0 :
+    {}
 | APSL_1_1 :
     {}
-| APSL_1_2 :
+| APL_1_0 :
     {}
+| APSL_2_0 :
+    {}
 | Artistic_1_0_cl8 :
     {}
-| Artistic_1_0_Perl :
+| APSL_1_2 :
     {}
-| APSL_2_0 :
+| Artistic_1_0_Perl :
     {}
 | Artistic_1_0 :
     {}
-| Artistic_2_0 :
+| Bahyph :
     {}
 | Barr :
     {}
-| Beerware :
+| Artistic_2_0 :
     {}
-| Bahyph :
+| BitTorrent_1_0 :
     {}
 | BitTorrent_1_1 :
     {}
-| Borceux :
+| Beerware :
     {}
-| BitTorrent_1_0 :
+| BSD_1_Clause :
     {}
 | BSD_2_Clause_FreeBSD :
     {}
-| BSD_2_Clause_NetBSD :
+| Borceux :
     {}
-| BSD_1_Clause :
+| BSD_2_Clause_NetBSD :
     {}
 | BSD_2_Clause_Patent :
     {}
-| BSD_2_Clause :
+| BSD_3_Clause_Attribution :
     {}
 | BSD_3_Clause_Clear :
     {}
-| BSD_3_Clause_LBNL :
-    {}
-| BSD_3_Clause_Attribution :
+| BSD_2_Clause :
     {}
 | BSD_3_Clause_No_Nuclear_License_2014 :
     {}
 | BSD_3_Clause_No_Nuclear_License :
     {}
+| BSD_3_Clause_LBNL :
+    {}
 | BSD_3_Clause :
     {}
 | BSD_4_Clause_UC :
@@ -264,124 +268,126 @@
     {}
 | EUPL_1_0 :
     {}
-| Eurosym :
-    {}
 | Fair :
     {}
-| FreeImage :
+| Frameworx_1_0 :
     {}
-| FSFAP :
+| Eurosym :
     {}
-| Frameworx_1_0 :
+| FSFAP :
     {}
 | FSFUL :
     {}
+| FreeImage :
+    {}
 | FSFULLR :
     {}
-| GFDL_1_1_only :
+| FTL :
     {}
 | GFDL_1_1_or_later :
     {}
-| FTL :
+| GFDL_1_2_only :
     {}
-| GFDL_1_2_or_later :
+| GFDL_1_1_only :
     {}
 | GFDL_1_3_only :
     {}
-| GFDL_1_2_only :
+| GFDL_1_3_or_later :
     {}
-| Giftware :
+| GFDL_1_2_or_later :
     {}
 | GL2PS :
     {}
-| GFDL_1_3_or_later :
-    {}
 | Glide :
     {}
+| Giftware :
+    {}
 | Glulxe :
     {}
-| GPL_1_0_only :
+| Gnuplot :
     {}
 | GPL_1_0_or_later :
     {}
-| Gnuplot :
+| GPL_2_0_only :
     {}
-| GPL_2_0_or_later :
+| GPL_1_0_only :
     {}
 | GPL_3_0_only :
     {}
-| GPL_2_0_only :
+| GPL_3_0_or_later :
     {}
-| GSOAP_1_3b :
+| GPL_2_0_or_later :
     {}
 | HaskellReport :
     {}
-| GPL_3_0_or_later :
-    {}
 | HPND :
     {}
+| GSOAP_1_3b :
+    {}
 | IBM_pibs :
     {}
-| IJG :
+| ICU :
     {}
 | ImageMagick :
     {}
-| ICU :
+| IMatix :
     {}
-| Imlib2 :
+| IJG :
     {}
 | Info_ZIP :
     {}
-| IMatix :
+| Intel_ACPI :
     {}
-| Intel :
+| Imlib2 :
     {}
 | Interbase_1_0 :
     {}
-| Intel_ACPI :
-    {}
 | IPA :
     {}
+| Intel :
+    {}
 | IPL_1_0 :
     {}
-| JasPer_2_0 :
+| ISC :
     {}
 | JSON :
     {}
-| ISC :
-    {}
 | LAL_1_2 :
     {}
+| JasPer_2_0 :
+    {}
 | LAL_1_3 :
     {}
-| Leptonica :
+| Latex2e :
     {}
 | LGPL_2_0_only :
     {}
-| Latex2e :
-    {}
 | LGPL_2_0_or_later :
     {}
+| Leptonica :
+    {}
 | LGPL_2_1_only :
     {}
-| LGPL_3_0_only :
+| LGPL_2_1_or_later :
     {}
 | LGPL_3_0_or_later :
     {}
-| LGPL_2_1_or_later :
+| LGPLLR :
     {}
-| Libpng :
+| LGPL_3_0_only :
     {}
 | Libtiff :
     {}
-| LGPLLR :
+| LiLiQ_P_1_1 :
     {}
-| LiLiQ_R_1_1 :
+| Libpng :
     {}
 | LiLiQ_Rplus_1_1 :
     {}
-| LiLiQ_P_1_1 :
+| Linux_OpenIB :
     {}
+| LiLiQ_R_1_1 :
+    {}
 | LPL_1_0 :
     {}
 | LPL_1_02 :
@@ -392,15 +398,17 @@
     {}
 | LPPL_1_0 :
     {}
-| LPPL_1_3a :
-    {}
 | LPPL_1_3c :
     {}
-| MirOS :
+| MakeIndex :
     {}
+| LPPL_1_3a :
+    {}
+| MIT_0 :
+    {}
 | MIT_advertising :
     {}
-| MakeIndex :
+| MirOS :
     {}
 | MIT_CMU :
     {}
@@ -434,48 +442,50 @@
     {}
 | MTLL :
     {}
-| NASA_1_3 :
-    {}
 | Naumen :
     {}
-| NCSA :
+| NBPL_1_0 :
     {}
-| Net_SNMP :
+| NASA_1_3 :
     {}
-| NBPL_1_0 :
+| Net_SNMP :
     {}
 | NetCDF :
     {}
+| NCSA :
+    {}
 | Newsletr :
     {}
-| NLOD_1_0 :
+| NGPL :
     {}
 | NLPL :
     {}
-| NGPL :
+| Nokia :
     {}
-| NOSL :
+| NLOD_1_0 :
     {}
 | Noweb :
     {}
-| Nokia :
+| NPL_1_0 :
     {}
-| NPL_1_1 :
+| NOSL :
     {}
 | NPOSL_3_0 :
     {}
-| NPL_1_0 :
-    {}
 | NRL :
     {}
+| NPL_1_1 :
+    {}
 | NTP :
     {}
-| OCLC_2_0 :
+| OCCT_PL :
     {}
 | ODbL_1_0 :
     {}
-| OCCT_PL :
+| ODC_By_1_0 :
     {}
+| OCLC_2_0 :
+    {}
 | OFL_1_1 :
     {}
 | OGTSL :
@@ -520,103 +530,107 @@
     {}
 | OML :
     {}
-| OSET_PL_2_1 :
-    {}
 | OSL_1_0 :
     {}
-| OSL_2_0 :
+| OSL_1_1 :
     {}
-| OSL_2_1 :
+| OSET_PL_2_1 :
     {}
-| OSL_1_1 :
+| OSL_2_1 :
     {}
 | OSL_3_0 :
     {}
+| OSL_2_0 :
+    {}
 | PDDL_1_0 :
     {}
-| PHP_3_01 :
+| PHP_3_0 :
     {}
 | Plexus :
     {}
-| PHP_3_0 :
+| PostgreSQL :
     {}
-| Psfrag :
+| PHP_3_01 :
     {}
 | Psutils :
     {}
-| PostgreSQL :
+| Python_2_0 :
     {}
-| Qhull :
+| Psfrag :
     {}
 | QPL_1_0 :
     {}
-| Python_2_0 :
-    {}
 | Rdisc :
     {}
+| Qhull :
+    {}
 | RHeCos_1_1 :
     {}
-| RPL_1_5 :
+| RPL_1_1 :
     {}
 | RPSL_1_0 :
     {}
-| RPL_1_1 :
+| RSA_MD :
     {}
-| RSCPL :
+| RPL_1_5 :
     {}
 | Ruby :
     {}
-| RSA_MD :
+| SAX_PD :
     {}
-| Saxpath :
+| RSCPL :
     {}
 | SCEA :
     {}
-| SAX_PD :
-    {}
 | Sendmail :
     {}
+| Saxpath :
+    {}
 | SGI_B_1_0 :
     {}
-| SGI_B_2_0 :
+| SGI_B_1_1 :
     {}
 | SimPL_2_0 :
     {}
-| SGI_B_1_1 :
+| SISSL_1_2 :
     {}
-| SISSL :
+| SGI_B_2_0 :
     {}
 | Sleepycat :
     {}
-| SISSL_1_2 :
+| SMLNJ :
     {}
-| SMPPL :
+| SISSL :
     {}
 | SNIA :
     {}
-| SMLNJ :
-    {}
 | Spencer_86 :
     {}
+| SMPPL :
+    {}
 | Spencer_94 :
     {}
-| SPL_1_0 :
+| Spencer_99 :
     {}
 | SugarCRM_1_1_3 :
     {}
-| Spencer_99 :
-    {}
 | SWL :
     {}
-| TCL :
+| SPL_1_0 :
     {}
-| TMate :
+| TCP_wrappers :
     {}
-| TORQUE_1_1 :
+| TMate :
     {}
-| TCP_wrappers :
+| TCL :
     {}
 | TOSL :
+    {}
+| TU_Berlin_1_0 :
+    {}
+| TORQUE_1_1 :
+    {}
+| TU_Berlin_2_0 :
     {}
 | Unicode_DFS_2015 :
     {}
diff --git a/exe/Main.hs b/exe/Main.hs
--- a/exe/Main.hs
+++ b/exe/Main.hs
@@ -30,7 +30,6 @@
 import DhallToCabal
 import qualified Paths_dhall_to_cabal as Paths
 
-import qualified Data.HashMap.Strict.InsOrd as InsOrdHashMap
 import qualified Data.Text.IO as StrictText
 import qualified Data.Text.Prettyprint.Doc as Pretty
 import qualified Data.Text.Prettyprint.Doc.Render.Text as Pretty
@@ -38,6 +37,7 @@
 import qualified Dhall.Core as Dhall
 import qualified Dhall.Core as Expr ( Expr(..), Var(..), shift )
 import qualified Distribution.PackageDescription as Cabal
+import qualified Dhall.Map as Map
 import qualified Dhall.Parser
 import qualified Dhall.TypeCheck as Dhall
 import qualified Distribution.PackageDescription.PrettyPrint as Cabal
@@ -487,22 +487,22 @@
 
       let
         intersection =
-          InsOrdHashMap.intersectionWith (==) left right
+          Map.intersectionWith (==) left right
 
       -- The right record cannot have any fields not in left.
-      guard ( InsOrdHashMap.null ( InsOrdHashMap.difference right left ) )
+      guard ( null ( Map.difference right left ) )
 
       -- We must have at least one field with a common name
-      guard ( not ( InsOrdHashMap.null intersection ) )
+      guard ( not ( null intersection ) )
 
       -- All common fields must have identical types
       guard ( and intersection )
 
       let
         extra =
-          InsOrdHashMap.difference left right
+          Map.difference left right
 
-      guard ( not ( InsOrdHashMap.null extra ) )
+      guard ( not ( null extra ) )
 
       return ( Expr.Record extra )
 
@@ -574,6 +574,12 @@
             <$> go t v
             <*> ( traverse ( `go` v ) elems )
 
+        Expr.Some a ->
+          Expr.Some <$> go a v
+
+        Expr.None ->
+          pure Expr.None
+
         Expr.Record fields ->
           Expr.Record <$> traverse ( `go` v ) fields
 
@@ -603,6 +609,12 @@
 
         Expr.Project e fs ->
           Expr.Project <$> go e v <*> pure fs
+
+        Expr.ImportAlt l r ->
+          Expr.ImportAlt <$> go l v <*> go r v
+
+        Expr.IntegerToDouble ->
+          pure Expr.IntegerToDouble
 
         Expr.Embed{} ->
           pure e
diff --git a/golden-tests/cabal-to-dhall/SPDX.dhall b/golden-tests/cabal-to-dhall/SPDX.dhall
--- a/golden-tests/cabal-to-dhall/SPDX.dhall
+++ b/golden-tests/cabal-to-dhall/SPDX.dhall
@@ -13,24 +13,24 @@
             ( prelude.SPDX.or
               ( prelude.SPDX.license
                 (prelude.types.LicenseId.AGPL_3_0_or_later {=})
-                ( [ prelude.types.LicenseExceptionId.Classpath_exception_2_0 {=}
-                  ] : Optional types.LicenseExceptionId
+                ( Some
+                  (prelude.types.LicenseExceptionId.Classpath_exception_2_0 {=})
                 )
               )
               ( prelude.SPDX.licenseVersionOrLater
                 (prelude.types.LicenseId.Apache_2_0 {=})
-                ([] : Optional types.LicenseExceptionId)
+                (None types.LicenseExceptionId)
               )
             )
             ( prelude.SPDX.or
               ( prelude.SPDX.ref
                 "MyFancyLicense"
-                ([] : Optional types.LicenseExceptionId)
+                (None types.LicenseExceptionId)
               )
               ( prelude.SPDX.refWithFile
                 "MyFancierLicense"
                 "LICENSE.txt"
-                ([] : Optional types.LicenseExceptionId)
+                (None types.LicenseExceptionId)
               )
             )
           )
diff --git a/golden-tests/cabal-to-dhall/conditional-dependencies.dhall b/golden-tests/cabal-to-dhall/conditional-dependencies.dhall
--- a/golden-tests/cabal-to-dhall/conditional-dependencies.dhall
+++ b/golden-tests/cabal-to-dhall/conditional-dependencies.dhall
@@ -10,7 +10,8 @@
       , cabal-version =
           prelude.v "2.0"
       , library =
-          [   λ(config : types.Config)
+          Some
+          (   λ(config : types.Config)
             →       if config.impl
                        (prelude.types.Compilers.GHC {=})
                        ( prelude.unionVersionRanges
@@ -58,7 +59,7 @@
                     ⫽ { build-depends =
                           [ { bounds = prelude.anyVersion, package = "A" } ]
                       }
-          ] : Optional (types.Config → types.Library)
+          )
       , license =
           prelude.types.Licenses.Unspecified {=}
       }
diff --git a/golden-tests/cabal-to-dhall/default-license-2.2.cabal b/golden-tests/cabal-to-dhall/default-license-2.2.cabal
new file mode 100644
--- /dev/null
+++ b/golden-tests/cabal-to-dhall/default-license-2.2.cabal
@@ -0,0 +1,3 @@
+cabal-version: 2.2
+name: test
+version: 1.0
diff --git a/golden-tests/cabal-to-dhall/default-license-2.2.dhall b/golden-tests/cabal-to-dhall/default-license-2.2.dhall
new file mode 100644
--- /dev/null
+++ b/golden-tests/cabal-to-dhall/default-license-2.2.dhall
@@ -0,0 +1,5 @@
+    let prelude = ./../../dhall/prelude.dhall
+
+in  let types = ./../../dhall/types.dhall
+
+in  prelude.defaults.Package ⫽ { name = "test", version = prelude.v "1.0" }
diff --git a/golden-tests/cabal-to-dhall/gh-36.dhall b/golden-tests/cabal-to-dhall/gh-36.dhall
--- a/golden-tests/cabal-to-dhall/gh-36.dhall
+++ b/golden-tests/cabal-to-dhall/gh-36.dhall
@@ -21,7 +21,8 @@
       , cabal-version =
           prelude.v "2.0"
       , library =
-          [   λ(config : types.Config)
+          Some
+          (   λ(config : types.Config)
             →       if config.impl
                        (prelude.types.Compilers.GHC {=})
                        ( prelude.unionVersionRanges
@@ -171,5 +172,5 @@
                     ⫽ { cpp-options = [ "-DWAI_SERVLET_DEBUG" ] }
               
               else  prelude.defaults.Library
-          ] : Optional (types.Config → types.Library)
+          )
       }
diff --git a/golden-tests/cabal-to-dhall/mixins-no-signatures.cabal b/golden-tests/cabal-to-dhall/mixins-no-signatures.cabal
new file mode 100644
--- /dev/null
+++ b/golden-tests/cabal-to-dhall/mixins-no-signatures.cabal
@@ -0,0 +1,9 @@
+cabal-version: 2.2
+name: mixins-test
+version: 0
+
+library
+  mixins:
+    foo,
+    bar (Some.Module, Some.Other.Module, Third.Module as Renamed),
+    baz hiding (Hidden, Also.Hidden)
diff --git a/golden-tests/cabal-to-dhall/mixins-no-signatures.dhall b/golden-tests/cabal-to-dhall/mixins-no-signatures.dhall
new file mode 100644
--- /dev/null
+++ b/golden-tests/cabal-to-dhall/mixins-no-signatures.dhall
@@ -0,0 +1,54 @@
+    let prelude = ./../../dhall/prelude.dhall
+
+in  let types = ./../../dhall/types.dhall
+
+in    prelude.defaults.Package
+    ⫽ { name =
+          "mixins-test"
+      , version =
+          prelude.v "0"
+      , library =
+          Some
+          (   λ(config : types.Config)
+            →   prelude.defaults.Library
+              ⫽ { mixins =
+                    [ { package =
+                          "foo"
+                      , renaming =
+                          { provides =
+                              prelude.types.ModuleRenaming.default {=}
+                          , requires =
+                              prelude.types.ModuleRenaming.default {=}
+                          }
+                      }
+                    , { package =
+                          "bar"
+                      , renaming =
+                          { provides =
+                              prelude.types.ModuleRenaming.renaming
+                              [ { rename = "Some.Module", to = "Some.Module" }
+                              , { rename =
+                                    "Some.Other.Module"
+                                , to =
+                                    "Some.Other.Module"
+                                }
+                              , { rename = "Third.Module", to = "Renamed" }
+                              ]
+                          , requires =
+                              prelude.types.ModuleRenaming.default {=}
+                          }
+                      }
+                    , { package =
+                          "baz"
+                      , renaming =
+                          { provides =
+                              prelude.types.ModuleRenaming.hiding
+                              [ "Hidden", "Also.Hidden" ]
+                          , requires =
+                              prelude.types.ModuleRenaming.default {=}
+                          }
+                      }
+                    ]
+                }
+          )
+      }
diff --git a/golden-tests/cabal-to-dhall/otheros.dhall b/golden-tests/cabal-to-dhall/otheros.dhall
--- a/golden-tests/cabal-to-dhall/otheros.dhall
+++ b/golden-tests/cabal-to-dhall/otheros.dhall
@@ -10,12 +10,13 @@
       , cabal-version =
           prelude.v "2.0"
       , library =
-          [   λ(config : types.Config)
+          Some
+          (   λ(config : types.Config)
             →       if config.os (prelude.types.OSs.OtherOS { _1 = "multics" })
               
               then    prelude.defaults.Library
                     ⫽ { exposed-modules = [ "A", "B" ] }
               
               else  prelude.defaults.Library ⫽ { exposed-modules = [ "A" ] }
-          ] : Optional (types.Config → types.Library)
+          )
       }
diff --git a/golden-tests/cabal-to-dhall/sourcerepo-defaults.dhall b/golden-tests/cabal-to-dhall/sourcerepo-defaults.dhall
--- a/golden-tests/cabal-to-dhall/sourcerepo-defaults.dhall
+++ b/golden-tests/cabal-to-dhall/sourcerepo-defaults.dhall
@@ -10,15 +10,15 @@
       , source-repos =
           [   prelude.defaults.SourceRepo
             ⫽ { type =
-                  [ prelude.types.RepoType.Git {=} ] : Optional types.RepoType
+                  Some (prelude.types.RepoType.Git {=})
               , location =
-                  [ "example.com" ] : Optional Text
+                  Some "example.com"
               }
           ,   prelude.defaults.SourceRepo
             ⫽ { type =
-                  [ prelude.types.RepoType.Darcs {=} ] : Optional types.RepoType
+                  Some (prelude.types.RepoType.Darcs {=})
               , location =
-                  [ "example.org" ] : Optional Text
+                  Some "example.org"
               , kind =
                   prelude.types.RepoKind.RepoThis {=}
               }
diff --git a/golden-tests/dhall-to-cabal/allrightsreserved-2.0.cabal b/golden-tests/dhall-to-cabal/allrightsreserved-2.0.cabal
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/allrightsreserved-2.0.cabal
@@ -0,0 +1,6 @@
+cabal-version: 2.0
+name: foo
+version: 0
+license: AllRightsReserved
+
+library
diff --git a/golden-tests/dhall-to-cabal/allrightsreserved-2.0.dhall b/golden-tests/dhall-to-cabal/allrightsreserved-2.0.dhall
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/allrightsreserved-2.0.dhall
@@ -0,0 +1,9 @@
+   let prelude = ../../dhall/prelude.dhall
+in let types = ../../dhall/types.dhall
+in   prelude.defaults.Package
+  // { name = "foo"
+     , version = prelude.v "0"
+     , cabal-version = prelude.v "2.0"
+     , license = prelude.types.Licenses.AllRightsReserved {=}
+     , library = prelude.unconditional.library prelude.defaults.Library
+     }
diff --git a/golden-tests/dhall-to-cabal/allrightsreserved-2.2.cabal b/golden-tests/dhall-to-cabal/allrightsreserved-2.2.cabal
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/allrightsreserved-2.2.cabal
@@ -0,0 +1,6 @@
+cabal-version: 2.2
+name: foo
+version: 0
+license: NONE
+
+library
diff --git a/golden-tests/dhall-to-cabal/allrightsreserved-2.2.dhall b/golden-tests/dhall-to-cabal/allrightsreserved-2.2.dhall
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/allrightsreserved-2.2.dhall
@@ -0,0 +1,9 @@
+   let prelude = ../../dhall/prelude.dhall
+in let types = ../../dhall/types.dhall
+in   prelude.defaults.Package
+  // { name = "foo"
+     , version = prelude.v "0"
+     , cabal-version = prelude.v "2.2"
+     , license = prelude.types.Licenses.AllRightsReserved {=}
+     , library = prelude.unconditional.library prelude.defaults.Library
+     }
diff --git a/golden-tests/dhall-to-cabal/default-license-2.2.cabal b/golden-tests/dhall-to-cabal/default-license-2.2.cabal
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/default-license-2.2.cabal
@@ -0,0 +1,6 @@
+cabal-version: 2.2
+name: foo
+version: 0
+license: NONE
+
+library
diff --git a/golden-tests/dhall-to-cabal/default-license-2.2.dhall b/golden-tests/dhall-to-cabal/default-license-2.2.dhall
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/default-license-2.2.dhall
@@ -0,0 +1,8 @@
+   let prelude = ../../dhall/prelude.dhall
+in let types = ../../dhall/types.dhall
+in   prelude.defaults.Package
+  // { name = "foo"
+     , version = prelude.v "0"
+     , cabal-version = prelude.v "2.2"
+     , library = prelude.unconditional.library prelude.defaults.Library
+     }
diff --git a/golden-tests/dhall-to-cabal/mixins-no-signatures.cabal b/golden-tests/dhall-to-cabal/mixins-no-signatures.cabal
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/mixins-no-signatures.cabal
@@ -0,0 +1,9 @@
+cabal-version: 2.2
+name: mixins-test
+version: 0
+
+library
+  mixins:
+    foo,
+    bar (Some.Module, Some.Other.Module, Third.Module as Renamed),
+    baz hiding (Hidden, Also.Hidden)
diff --git a/golden-tests/dhall-to-cabal/mixins-no-signatures.dhall b/golden-tests/dhall-to-cabal/mixins-no-signatures.dhall
new file mode 100644
--- /dev/null
+++ b/golden-tests/dhall-to-cabal/mixins-no-signatures.dhall
@@ -0,0 +1,53 @@
+    let prelude = ./../../dhall/prelude.dhall
+
+in  let types = ./../../dhall/types.dhall
+
+in    prelude.defaults.Package
+    ⫽ { name =
+          "mixins-test"
+      , version =
+          prelude.v "0"
+      , library =
+          [   λ(config : types.Config)
+            →   prelude.defaults.Library
+              ⫽ { mixins =
+                    [ { package =
+                          "foo"
+                      , renaming =
+                          { provides =
+                              prelude.types.ModuleRenaming.default {=}
+                          , requires =
+                              prelude.types.ModuleRenaming.default {=}
+                          }
+                      }
+                    , { package =
+                          "bar"
+                      , renaming =
+                          { provides =
+                              prelude.types.ModuleRenaming.renaming
+                              [ { rename = "Some.Module", to = "Some.Module" }
+                              , { rename =
+                                    "Some.Other.Module"
+                                , to =
+                                    "Some.Other.Module"
+                                }
+                              , { rename = "Third.Module", to = "Renamed" }
+                              ]
+                          , requires =
+                              prelude.types.ModuleRenaming.default {=}
+                          }
+                      }
+                    , { package =
+                          "baz"
+                      , renaming =
+                          { provides =
+                              prelude.types.ModuleRenaming.hiding
+                              [ "Hidden", "Also.Hidden" ]
+                          , requires =
+                              prelude.types.ModuleRenaming.default {=}
+                          }
+                      }
+                    ]
+                }
+          ] : Optional (types.Config → types.Library)
+      }
diff --git a/lib/CabalToDhall.hs b/lib/CabalToDhall.hs
--- a/lib/CabalToDhall.hs
+++ b/lib/CabalToDhall.hs
@@ -23,12 +23,12 @@
 import Numeric.Natural ( Natural )
 
 import qualified Data.ByteString as ByteString
-import qualified Data.HashMap.Strict.InsOrd as Map
 import qualified Data.Sequence as Seq
 import qualified Data.Text as StrictText
 import qualified Dhall
 import qualified Dhall.Core
 import qualified Dhall.Core as Expr ( Expr(..), Var(..) )
+import qualified Dhall.Map as Map
 import qualified Dhall.Parser
 import qualified Dhall.TypeCheck
 import qualified Distribution.Compiler as Cabal
@@ -148,7 +148,7 @@
 
 type Default s a
    = ( PreludeReference -> Expr.Expr s a )
-   -> Map.InsOrdHashMap StrictText.Text ( Expr.Expr s a )
+   -> Map.Map StrictText.Text ( Expr.Expr s a )
 
 
 getDefault
@@ -208,7 +208,7 @@
   -> Expr.Expr s a
   -> ( StrictText.Text, Expr.Expr s a )
 emptyOptionalDefault name ty =
-  ( name, Expr.OptionalLit ty Nothing )
+  ( name, Expr.App Expr.None ty )
 
 
 textFieldDefault
@@ -228,7 +228,8 @@
 compilerOptionsDefault :: Default s a
 compilerOptionsDefault _resolve =
   ( Map.fromList
-    [ emptyListDefault "GHC" Expr.Text
+    [ emptyListDefault "Eta" Expr.Text
+    , emptyListDefault "GHC" Expr.Text
     , emptyListDefault "GHCJS" Expr.Text
     , emptyListDefault "HBC" Expr.Text
     , emptyListDefault "Helium" Expr.Text
@@ -433,9 +434,9 @@
 
 nonDefaultFields
   :: ( Eq a )
-  => Map.InsOrdHashMap StrictText.Text ( Expr.Expr s a )
-  -> Map.InsOrdHashMap StrictText.Text ( Expr.Expr s a )
-  -> Map.InsOrdHashMap StrictText.Text ( Expr.Expr s a )
+  => Map.Map StrictText.Text ( Expr.Expr s a )
+  -> Map.Map StrictText.Text ( Expr.Expr s a )
+  -> Map.Map StrictText.Text ( Expr.Expr s a )
 nonDefaultFields defs fields =
   let
     withoutDefaults = Map.difference fields defs
@@ -470,7 +471,7 @@
 newtype RecordInputType a =
   RecordInputType
     { _unRecordInputType ::
-        Map.InsOrdHashMap Dhall.Text ( Dhall.InputType a )
+        Map.Map Dhall.Text ( Dhall.InputType a )
     }
   deriving ( Semigroup, Monoid )
 
@@ -751,9 +752,9 @@
     { _unUnion ::
         ( a ->
           ( First ( Dhall.Text, DhallExpr )
-          , Map.InsOrdHashMap Dhall.Text DhallExpr
+          , Map.Map Dhall.Text DhallExpr
           )
-        , Map.InsOrdHashMap Dhall.Text DhallExpr
+        , Map.Map Dhall.Text DhallExpr
         )
     }
   deriving ( Semigroup, Monoid )
@@ -793,7 +794,9 @@
 maybeToDhall t =
   Dhall.InputType
     { Dhall.embed =
-        \a -> Expr.OptionalLit ( Dhall.declared t ) ( Dhall.embed t <$> a )
+        \a -> case a of
+            Nothing -> Expr.App Expr.None (Dhall.declared t)
+            Just x  -> Expr.Some ( Dhall.embed t x )
     , Dhall.declared = Expr.App Expr.Optional ( Dhall.declared t )
     }
 
@@ -829,6 +832,9 @@
   in
   Dhall.InputType
     { Dhall.embed = \case
+        Cabal.Eta ->
+          constructor "Eta" ( Expr.RecordLit mempty )
+
         Cabal.GHC ->
           constructor "GHC" ( Expr.RecordLit mempty )
 
@@ -1496,15 +1502,41 @@
 
 moduleRenaming :: Dhall.InputType Cabal.ModuleRenaming
 moduleRenaming =
-  ( \( Cabal.ModuleRenaming a ) -> a ) >$<
-  listOf
-    ( runRecordInputType
-        ( mconcat
-            [ recordField "rename" ( ( \( a, _ ) -> a ) >$< moduleName )
-            , recordField "to" ( ( \( _, a ) -> a ) >$< moduleName )
-            ]
-        )
-    )
+  Dhall.InputType
+    { Dhall.embed =
+        \a ->
+          case a of
+            Cabal.ModuleRenaming renamed ->
+              Expr.App
+                ( Expr.Var "prelude" `Expr.Field` "types" `Expr.Field` "ModuleRenaming" `Expr.Field` "renaming" )
+                ( Expr.ListLit
+                    Nothing
+                    ( fmap
+                        (\ ( src, dst ) ->
+                           Expr.RecordLit
+                             ( Map.fromList
+                                 [ ( "rename", Dhall.embed moduleName src )
+                                 , ( "to", Dhall.embed moduleName dst )
+                                 ]
+                             )
+                        )
+                        ( Seq.fromList renamed )
+                    )
+                )
+            Cabal.DefaultRenaming ->
+              Expr.App
+                ( Expr.Var "prelude" `Expr.Field` "types" `Expr.Field` "ModuleRenaming" `Expr.Field` "default" )
+                ( Expr.RecordLit mempty )
+            Cabal.HidingRenaming hidden ->
+              Expr.App
+                ( Expr.Var "prelude" `Expr.Field` "types" `Expr.Field` "ModuleRenaming" `Expr.Field` "hiding" )
+                ( Expr.ListLit
+                    Nothing
+                    ( Dhall.embed moduleName <$> Seq.fromList hidden )
+                )
+    , Dhall.declared =
+        Expr.Var "types" `Expr.Field` "ModuleRenaming"
+    }
 
 
 benchmark :: Dhall.InputType Cabal.Benchmark
diff --git a/lib/Dhall/Extra.hs b/lib/Dhall/Extra.hs
--- a/lib/Dhall/Extra.hs
+++ b/lib/Dhall/Extra.hs
@@ -16,14 +16,14 @@
 import Data.List ( sortBy )
 import Data.Ord ( comparing )
 
-import qualified Data.HashMap.Strict.InsOrd as Map
 import qualified Data.Text as StrictText
 import qualified Dhall
 import qualified Dhall.Core as Dhall ( Expr )
 import qualified Dhall.Core as Expr ( Expr(..) )
+import qualified Dhall.Map as Map
 
 
-makeUnion :: Map.InsOrdHashMap StrictText.Text ( Dhall.Type a ) -> Dhall.Type a
+makeUnion :: Map.Map StrictText.Text ( Dhall.Type a ) -> Dhall.Type a
 makeUnion alts =
   let
     extract expr = do
@@ -47,7 +47,7 @@
   a { Dhall.extract = join . Dhall.extract a }
 
 
-sortInsOrdHashMap :: ( Hashable k, Ord k ) => Map.InsOrdHashMap k v -> Map.InsOrdHashMap k v
+sortInsOrdHashMap :: Ord k => Map.Map k v -> Map.Map k v
 sortInsOrdHashMap =
   Map.fromList . sortBy ( comparing fst ) . Map.toList
 
diff --git a/lib/DhallLocation.hs b/lib/DhallLocation.hs
--- a/lib/DhallLocation.hs
+++ b/lib/DhallLocation.hs
@@ -34,14 +34,18 @@
                 { Dhall.Core.hash =
                     Nothing
                 , Dhall.Core.importType =
-                    Dhall.Core.URL
-                      "https://raw.githubusercontent.com"
-                      ( Dhall.Core.File
-                         ( Dhall.Core.Directory [ "dhall", version, "dhall-to-cabal", "dhall-lang" ] )
-                         "prelude.dhall"
+                    Dhall.Core.Remote
+                      ( Dhall.Core.URL
+                          Dhall.Core.HTTPS
+                          "https://raw.githubusercontent.com"
+                          ( Dhall.Core.File
+                             ( Dhall.Core.Directory [ "dhall", version, "dhall-to-cabal", "dhall-lang" ] )
+                             "prelude.dhall"
+                          )
+                          Nothing
+                          Nothing
+                          Nothing
                       )
-                      ""
-                      Nothing
                 }
           , Dhall.Core.importMode =
               Dhall.Core.Code
@@ -54,14 +58,18 @@
                 { Dhall.Core.hash =
                     Nothing
                 , Dhall.Core.importType =
-                    Dhall.Core.URL
-                      "https://raw.githubusercontent.com"
-                      ( Dhall.Core.File
-                         ( Dhall.Core.Directory [ "dhall", version, "dhall-to-cabal", "dhall-lang" ] )
-                         "types.dhall"
+                    Dhall.Core.Remote
+                      ( Dhall.Core.URL
+                          Dhall.Core.HTTPS
+                          "https://raw.githubusercontent.com"
+                          ( Dhall.Core.File
+                             ( Dhall.Core.Directory [ "dhall", version, "dhall-to-cabal", "dhall-lang" ] )
+                             "types.dhall"
+                          )
+                          Nothing
+                          Nothing
+                          Nothing
                       )
-                      ""
-                      Nothing
                 }
           , Dhall.Core.importMode =
               Dhall.Core.Code
diff --git a/lib/DhallToCabal.hs b/lib/DhallToCabal.hs
--- a/lib/DhallToCabal.hs
+++ b/lib/DhallToCabal.hs
@@ -4,7 +4,6 @@
 {-# language GADTs #-}
 {-# language LambdaCase #-}
 {-# language OverloadedStrings #-}
-{-# language PatternSynonyms #-}
 {-# language RecordWildCards #-}
 
 module DhallToCabal
@@ -43,9 +42,10 @@
 import Data.Maybe ( fromMaybe )
 import Data.Monoid ( (<>) )
 
-import qualified Data.HashMap.Strict.InsOrd as Map
 import qualified Data.Text as StrictText
 import qualified Dhall
+import qualified Dhall.Core
+import qualified Dhall.Map as Map
 import qualified Dhall.Parser
 import qualified Dhall.TypeCheck
 import qualified Distribution.Compiler as Cabal
@@ -74,7 +74,7 @@
 import qualified Language.Haskell.Extension as Cabal
 
 import qualified Dhall.Core as Expr
-  ( Chunks(..), Const(..), Expr(..), Var(..) )
+  ( Chunks(..), Const(..), Expr(..) )
 
 import Dhall.Extra
 import DhallToCabal.ConfigTree ( ConfigTree(..), toConfigTree )
@@ -176,14 +176,6 @@
   category <-
     Dhall.field "category" Dhall.string
 
-  -- Cabal documentation states
-  --
-  --   > YOU PROBABLY DON'T WANT TO USE THIS FIELD.
-  --
-  -- So I guess we won't use this field.
-  buildDepends <-
-    pure []
-
   setupBuildInfo <-
     Dhall.field "custom-setup" ( Dhall.maybe setupBuildInfo )
 
@@ -228,17 +220,15 @@
         ( error "Could not parse version" )
         ( Cabal.simpleParse ( StrictText.unpack text ) )
 
-    extract =
-      \case
-        LamArr _Version (LamArr _v v) ->
-          go v
-
-        e ->
-          error ( show e )
+    extract e =
+      go
+        ( Dhall.Core.normalize ( e `Expr.App` "Version" `Expr.App` "v" )
+            `asTypeOf` e
+        )
 
     go =
       \case
-        Expr.App ( V0 "v" ) ( Expr.TextLit ( Expr.Chunks [] text ) ) ->
+        Expr.App "v" ( Expr.TextLit ( Expr.Chunks [] text ) ) ->
           return ( parse text )
 
         e ->
@@ -248,8 +238,8 @@
       Expr.Pi "Version" ( Expr.Const Expr.Type )
         $ Expr.Pi
             "v"
-            ( Expr.Pi "_" ( Dhall.expected Dhall.string ) ( V0 "Version" ) )
-            ( V0 "Version" )
+            ( Expr.Pi "_" ( Dhall.expected Dhall.string ) "Version" )
+            "Version"
 
   in Dhall.Type { .. }
 
@@ -599,69 +589,74 @@
 
 
 
-pattern LamArr :: Expr.Expr s a -> Expr.Expr s a -> Expr.Expr s a
-pattern LamArr a b <- Expr.Lam _ a b
-
-
-
-pattern V0 :: Dhall.Text -> Expr.Expr s a
-pattern V0 v = Expr.Var ( Expr.V v 0 )
-
-
-
 versionRange :: Dhall.Type Cabal.VersionRange
 versionRange =
   let
-    extract =
-      \case
-        LamArr _VersionRange (LamArr _anyVersion (LamArr _noVersion (LamArr _thisVersion (LamArr _notThisVersion (LamArr _laterVersion (LamArr _earlierVersion (LamArr _orLaterVersion (LamArr _orEarlierVersion (LamArr _withinVersion (LamArr _majorBoundVersion (LamArr _unionVersionRanges (LamArr _intersectVersionRanges (LamArr _differenceVersionRanges (LamArr _invertVersionRange versionRange)))))))))))))) ->
-          go versionRange
-
-        _ ->
-          Nothing
+    extract e =
+      go
+        ( Dhall.Core.normalize
+            ( e
+                `Expr.App` "VersionRange"
+                `Expr.App` "anyVersion"
+                `Expr.App` "noVersion"
+                `Expr.App` "thisVersion"
+                `Expr.App` "notThisVersion"
+                `Expr.App` "laterVersion"
+                `Expr.App` "earlierVersion"
+                `Expr.App` "orLaterVersion"
+                `Expr.App` "orEarlierVersion"
+                `Expr.App` "withinVersion"
+                `Expr.App` "majorBoundVersion"
+                `Expr.App` "unionVersionRanges"
+                `Expr.App` "intersectVersionRanges"
+                `Expr.App` "differenceVersionRanges"
+                `Expr.App` "invertVersionRange"
+            )
+            `asTypeOf` e
+        )
 
     go =
       \case
-        V0 "anyVersion" ->
+        "anyVersion" ->
           return Cabal.anyVersion
 
-        V0 "noVersion" ->
+        "noVersion" ->
           return Cabal.noVersion
 
-        Expr.App ( V0 "thisVersion" ) components ->
+        Expr.App "thisVersion" components ->
           Cabal.thisVersion <$> Dhall.extract version components
 
-        Expr.App ( V0 "notThisVersion" ) components ->
+        Expr.App "notThisVersion" components ->
           Cabal.notThisVersion <$> Dhall.extract version components
 
-        Expr.App ( V0 "laterVersion" ) components ->
+        Expr.App "laterVersion" components ->
           Cabal.laterVersion <$> Dhall.extract version components
 
-        Expr.App ( V0 "earlierVersion" ) components ->
+        Expr.App "earlierVersion" components ->
           Cabal.earlierVersion <$> Dhall.extract version components
 
-        Expr.App ( V0 "orLaterVersion" ) components ->
+        Expr.App "orLaterVersion" components ->
           Cabal.orLaterVersion <$> Dhall.extract version components
 
-        Expr.App ( V0 "orEarlierVersion" ) components ->
+        Expr.App "orEarlierVersion" components ->
           Cabal.orEarlierVersion <$> Dhall.extract version components
 
-        Expr.App ( Expr.App ( V0 "unionVersionRanges" ) a ) b ->
+        Expr.App ( Expr.App "unionVersionRanges" a ) b ->
           Cabal.unionVersionRanges <$> go a <*> go b
 
-        Expr.App ( Expr.App ( V0 "intersectVersionRanges" ) a ) b ->
+        Expr.App ( Expr.App "intersectVersionRanges" a ) b ->
           Cabal.intersectVersionRanges <$> go a <*> go b
 
-        Expr.App ( Expr.App ( V0 "differenceVersionRanges" ) a ) b ->
+        Expr.App ( Expr.App "differenceVersionRanges" a ) b ->
           Cabal.differenceVersionRanges <$> go a <*> go b
 
-        Expr.App ( V0 "invertVersionRange" ) components ->
+        Expr.App "invertVersionRange" components ->
           Cabal.invertVersionRange <$> go components
 
-        Expr.App ( V0 "withinVersion" ) components ->
+        Expr.App "withinVersion" components ->
           Cabal.withinVersion <$> Dhall.extract version components
 
-        Expr.App ( V0 "majorBoundVersion" ) components ->
+        Expr.App "majorBoundVersion" components ->
           Cabal.majorBoundVersion <$> Dhall.extract version components
 
         _ ->
@@ -670,7 +665,7 @@
     expected =
       let
         versionRange =
-          V0 "VersionRange"
+          "VersionRange"
 
         versionToVersionRange =
           Expr.Pi
@@ -737,41 +732,48 @@
 spdxLicense :: Dhall.Type SPDX.LicenseExpression
 spdxLicense =
   let
-    extract =
-      \case
-        LamArr _spdx (LamArr _licenseExactVersion (LamArr _licenseVersionOrLater (LamArr _licenseRef (LamArr _licenseRefWithFile (LamArr _licenseAnd (LamArr _licenseOr license)))))) ->
-          go license
-
-        _ ->
-          Nothing
+    extract e =
+      go
+        ( Dhall.Core.normalize
+            ( e
+                `Expr.App` "SPDX"
+                `Expr.App` "license"
+                `Expr.App` "licenseVersionOrLater"
+                `Expr.App` "ref"
+                `Expr.App` "refWithFile"
+                `Expr.App` "and"
+                `Expr.App` "or"
+            )
+            `asTypeOf` e
+        )
 
     go =
       \case
-        Expr.App ( Expr.App ( V0 "license" ) identM ) exceptionMayM -> do
+        Expr.App ( Expr.App "license" identM ) exceptionMayM -> do
           ident <- Dhall.extract spdxLicenseId identM
           exceptionMay <- Dhall.extract ( Dhall.maybe spdxLicenseExceptionId ) exceptionMayM
           return ( SPDX.ELicense ( SPDX.ELicenseId ident ) exceptionMay )
 
-        Expr.App ( Expr.App ( V0 "licenseVersionOrLater" ) identM ) exceptionMayM -> do          
+        Expr.App ( Expr.App "licenseVersionOrLater" identM ) exceptionMayM -> do
           ident <- Dhall.extract spdxLicenseId identM
           exceptionMay <- Dhall.extract ( Dhall.maybe spdxLicenseExceptionId ) exceptionMayM
           return ( SPDX.ELicense ( SPDX.ELicenseIdPlus ident ) exceptionMay )
 
-        Expr.App ( Expr.App ( V0 "ref" ) identM ) exceptionMayM -> do
+        Expr.App ( Expr.App "ref" identM ) exceptionMayM -> do
           ident <- Dhall.extract Dhall.string identM
           exceptionMay <- Dhall.extract ( Dhall.maybe spdxLicenseExceptionId ) exceptionMayM
           return ( SPDX.ELicense ( SPDX.ELicenseRef ( SPDX.mkLicenseRef' Nothing ident ) ) exceptionMay )
 
-        Expr.App ( Expr.App ( Expr.App ( V0 "refWithFile" ) identM ) filenameM) exceptionMayM -> do
+        Expr.App ( Expr.App ( Expr.App "refWithFile" identM ) filenameM) exceptionMayM -> do
           ident <- Dhall.extract Dhall.string identM
           filename <- Dhall.extract Dhall.string filenameM
           exceptionMay <- Dhall.extract ( Dhall.maybe spdxLicenseExceptionId ) exceptionMayM
           return ( SPDX.ELicense ( SPDX.ELicenseRef ( SPDX.mkLicenseRef' ( Just filename ) ident ) ) exceptionMay )
 
-        Expr.App ( Expr.App ( V0 "and" ) a ) b ->
+        Expr.App ( Expr.App "and" a ) b ->
           SPDX.EAnd <$> go a <*> go b
 
-        Expr.App ( Expr.App ( V0 "or" ) a ) b ->
+        Expr.App ( Expr.App "or" a ) b ->
           SPDX.EOr <$> go a <*> go b
 
         _ ->
@@ -780,7 +782,7 @@
     expected =
       let
         licenseType =
-          V0 "SPDX"
+          "SPDX"
 
         licenseIdAndException
           = Expr.Pi "id" ( Dhall.expected spdxLicenseId )
@@ -863,7 +865,8 @@
 compilerOptions =
   Dhall.record $
     sequenceA
-      [ (,) <$> pure Cabal.GHC <*> Dhall.field "GHC" options
+      [ (,) <$> pure Cabal.Eta <*> Dhall.field "Eta" options
+      , (,) <$> pure Cabal.GHC <*> Dhall.field "GHC" options
       , (,) <$> pure Cabal.GHCJS <*> Dhall.field "GHCJS" options
       , (,) <$> pure Cabal.NHC <*> Dhall.field "NHC" options
       , (,) <$> pure Cabal.YHC <*> Dhall.field "YHC" options
@@ -985,7 +988,7 @@
       sortType Dhall.genericAuto
 
     unitType =
-      Expr.Record Map.empty
+      Expr.Record mempty
 
     extract expr = do
       Expr.UnionLit k v alts <-
@@ -1026,12 +1029,12 @@
   let
     extractConfVar body =
       case body of
-        Expr.App ( Expr.App ( Expr.Field ( V0 "config" ) "impl" ) compiler ) version ->
+        Expr.App ( Expr.App ( Expr.Field "config" "impl" ) compiler ) version ->
           Cabal.Impl
             <$> Dhall.extract compilerFlavor compiler
             <*> Dhall.extract versionRange version
 
-        Expr.App ( Expr.Field ( V0 "config" ) field ) x ->
+        Expr.App ( Expr.Field "config" field ) x ->
           case field of
             "os" ->
               Cabal.OS <$> Dhall.extract operatingSystem x
@@ -1326,10 +1329,25 @@
 
 moduleRenaming :: Dhall.Type Cabal.ModuleRenaming
 moduleRenaming =
-  fmap Cabal.ModuleRenaming $
-  Dhall.list $
-  Dhall.record $
-    (,) <$> Dhall.field "rename" moduleName <*> Dhall.field "to" moduleName
+  makeUnion
+    ( Map.fromList
+      [ ( "renaming"
+        , fmap Cabal.ModuleRenaming
+            ( Dhall.list
+              ( Dhall.record
+                ( (,) <$> Dhall.field "rename" moduleName <*> Dhall.field "to" moduleName )
+              )
+            )
+        )
+      , ( "default"
+        , Dhall.record ( pure Cabal.DefaultRenaming )
+        )
+      , ( "hiding"
+        , fmap Cabal.HidingRenaming
+            ( Dhall.list moduleName )
+        )
+      ]
+    )
 
 
 sortType :: Dhall.Type a -> Dhall.Type a
diff --git a/lib/DhallToCabal/ConfigTree.hs b/lib/DhallToCabal/ConfigTree.hs
--- a/lib/DhallToCabal/ConfigTree.hs
+++ b/lib/DhallToCabal/ConfigTree.hs
@@ -81,7 +81,7 @@
    )
 
   where
-    
+
     isConfigUse (App (Field (Var x') "os") _)           | v == x' = True
     isConfigUse (App (Field (Var x') "arch") _)         | v == x' = True
     isConfigUse (App (App (Field (Var x') "impl") _) _) | v == x' = True
@@ -100,94 +100,3 @@
 
 
 
-subExpr
-  :: Applicative f
-  => ( Expr s a -> f ( Expr s a ) ) -> Expr s a -> f ( Expr s a )
-subExpr f = \case
-  Lam a b c ->
-    Lam a <$> f b <*> f c
-
-  Pi a b c ->
-    Pi a <$> f b <*> f c
-
-  App a b ->
-    App <$> f a <*> f b
-
-  Let a b c d ->
-    Let a <$> traverse f b <*> f c <*> f d
-
-  Annot a b ->
-    Annot <$> f a <*> f b
-
-  BoolAnd a b ->
-    BoolAnd <$> f a <*> f b
-
-  BoolOr a b ->
-    BoolOr <$> f a <*> f b
-
-  BoolEQ a b ->
-    BoolEQ <$> f a <*> f b
-
-  BoolNE a b ->
-    BoolNE <$> f a <*> f b
-
-  BoolIf a b c ->
-    BoolIf <$> f a <*> f b <*> f c
-
-  NaturalPlus a b ->
-    NaturalPlus <$> f a <*> f b
-
-  NaturalTimes a b ->
-    NaturalTimes <$> f a <*> f b
-
-  TextLit (Chunks a b) ->
-    TextLit
-      <$>
-        ( Chunks
-            <$> traverse ( \(a,b) -> (,) <$> pure a <*> f b ) a <*> pure b
-        )
-
-  TextAppend a b ->
-    TextAppend <$> f a <*> f b
-
-  ListLit a b ->
-    ListLit <$> traverse f a <*> traverse f b
-
-  ListAppend a b ->
-    ListAppend <$> f a <*> f b
-
-  OptionalLit a b ->
-    OptionalLit <$> f a <*> traverse f b
-
-  Record a ->
-    Record <$> traverse f a
-
-  RecordLit a ->
-    RecordLit <$> traverse f a
-
-  Union a ->
-    Union <$> traverse f a
-
-  UnionLit a b c ->
-    UnionLit a <$> f b <*> traverse f c
-
-  Combine a b ->
-    Combine <$> f a <*> f b
-
-  Prefer a b ->
-    Prefer <$> f a <*> f b
-
-  Merge a b t ->
-    Merge <$> f a <*> f b <*> traverse f t
-
-  Constructors a ->
-    Constructors <$> f a
-
-  Field a b ->
-    Field <$> f a <*> pure b
-
-  Note a b ->
-    Note a <$> f b
-
-  e ->
-    pure e
diff --git a/tests/DhallToCabal/Tests.hs b/tests/DhallToCabal/Tests.hs
new file mode 100644
--- /dev/null
+++ b/tests/DhallToCabal/Tests.hs
@@ -0,0 +1,69 @@
+{-# language OverloadedStrings #-}
+
+module DhallToCabal.Tests
+  ( versionSpec
+  )
+  where
+
+import Data.Maybe ( fromMaybe )
+import Dhall.Core ( Const(..), Expr(..), Chunks(..) )
+
+import qualified Data.Text as StrictText
+import qualified Dhall
+import qualified Dhall.Core
+import qualified Dhall.Parser
+import qualified Dhall.TypeCheck
+import qualified DhallToCabal
+import qualified Distribution.Text as Cabal ( simpleParse )
+import qualified Test.Tasty
+import qualified Test.Tasty.HUnit
+
+
+versionSpec :: Test.Tasty.TestTree
+versionSpec =
+  Test.Tasty.testGroup
+    "version"
+    [ testExtraction
+        "version"
+        DhallToCabal.version
+        ( Lam
+            "Version"
+            ( Const Type )
+            ( Lam
+                "v"
+                ( Pi "_" ( Const Type ) ( Pi "_" Text "Version" ) )
+                ( App "v" ( TextLit ( Chunks [] "1.0.0" ) ) )
+            )
+        )
+        ( fromMaybe
+            ( error "Could not parse version" )
+            ( Cabal.simpleParse ( StrictText.unpack "1.0.0" ) )
+        ) ]
+
+
+testExtraction
+  :: ( Eq a, Show a )
+  => Test.Tasty.TestName
+  -> Dhall.Type a
+  -> Dhall.Core.Expr Dhall.Parser.Src Dhall.TypeCheck.X
+  -> a
+  -> Test.Tasty.TestTree
+testExtraction testName t expr expected =
+  Test.Tasty.testGroup
+    testName
+    [ Test.Tasty.HUnit.testCase
+        "original"
+        ( Just expected Test.Tasty.HUnit.@=? Dhall.extract t expr )
+    , Test.Tasty.HUnit.testCase
+        "alphaNormalize"
+        ( Just expected
+            Test.Tasty.HUnit.@=?
+              Dhall.extract t ( Dhall.Core.alphaNormalize expr )
+        )
+    , Test.Tasty.HUnit.testCase
+        "betaNormalize"
+        ( Just expected
+            Test.Tasty.HUnit.@=?
+              Dhall.extract t ( Dhall.Core.normalize expr )
+        )
+    ]
diff --git a/tests/Tests.hs b/tests/Tests.hs
new file mode 100644
--- /dev/null
+++ b/tests/Tests.hs
@@ -0,0 +1,12 @@
+module Main
+  ( main
+  )
+  where
+
+import qualified DhallToCabal.Tests
+import qualified Test.Tasty
+
+
+main :: IO ()
+main =
+  Test.Tasty.defaultMain DhallToCabal.Tests.versionSpec