diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # shake-cabal
 
+## 0.2.2.1
+
+  * Support `shake` 0.18.4
+
 ## 0.2.2.0
 
   * Export `CabalVersion` so `cabalOracle` is usable
diff --git a/shake-cabal.cabal b/shake-cabal.cabal
--- a/shake-cabal.cabal
+++ b/shake-cabal.cabal
@@ -1,43 +1,44 @@
-cabal-version: 1.18
-name: shake-cabal
-version: 0.2.1.1
-license: BSD3
-license-file: LICENSE
-copyright: Copyright: (c) 2018-2019 Vanessa McHale
-maintainer: vanessa.mchale@iohk.io
-author: Vanessa McHale
-bug-reports: https://hub.darcs.net/vmchale/ats/issues
-synopsis: Shake library for use with cabal
+cabal-version:   1.18
+name:            shake-cabal
+version:         0.2.2.1
+license:         BSD3
+license-file:    LICENSE
+copyright:       Copyright: (c) 2018-2019 Vanessa McHale
+maintainer:      vamchale@gmail.com
+author:          Vanessa McHale
+bug-reports:     https://github.com/vmchale/atspkg/issues
+synopsis:        Shake library for use with cabal
 description:
     A library for using [shake](http://hackage.haskell.org/package/shake) alongside [cabal](https://www.haskell.org/cabal/).
-category: Development
-build-type: Simple
-extra-doc-files: README.md
-                 CHANGELOG.md
 
+category:        Development
+build-type:      Simple
+extra-doc-files:
+    README.md
+    CHANGELOG.md
+
 source-repository head
-    type: darcs
-    location: https://hub.darcs.net/vmchale/ats
+    type:     git
+    location: git@github.com:vmchale/atspkg.git
+    subdir:   shake-cabal
 
 flag development
-    description:
-        Enable `-Werror`
-    default: False
-    manual: True
+    description: Enable `-Werror`
+    default:     False
+    manual:      True
 
 library
-    exposed-modules:
-        Development.Shake.Cabal
-    hs-source-dirs: src
-    other-modules:
-        Development.Shake.Cabal.Oracles
+    exposed-modules:  Development.Shake.Cabal
+    hs-source-dirs:   src
+    other-modules:    Development.Shake.Cabal.Oracles
     default-language: Haskell2010
-    other-extensions: DeriveAnyClass DeriveGeneric DeriveDataTypeable
-                      TypeFamilies
-    ghc-options: -Wall
+    other-extensions:
+        DeriveAnyClass DeriveGeneric DeriveDataTypeable TypeFamilies
+
+    ghc-options:      -Wall
     build-depends:
         base >=4.8 && <5,
-        shake >=0.14,
+        shake >=0.18.4,
         Cabal >=2.2,
         directory -any,
         composition-prelude -any,
@@ -50,8 +51,9 @@
         ghc-options: -Werror
 
     if impl(ghc >=8.0)
-        ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
-                     -Wredundant-constraints -Wnoncanonical-monad-instances
+        ghc-options:
+            -Wincomplete-uni-patterns -Wincomplete-record-updates
+            -Wredundant-constraints -Wnoncanonical-monad-instances
 
     if impl(ghc >=8.4)
         ghc-options: -Wmissing-export-lists
diff --git a/src/Development/Shake/Cabal.hs b/src/Development/Shake/Cabal.hs
--- a/src/Development/Shake/Cabal.hs
+++ b/src/Development/Shake/Cabal.hs
@@ -76,15 +76,15 @@
 extract :: CondTree a b c -> [c]
 extract (CondNode d _ []) = [d]
 extract (CondNode d _ bs) = d : (g =<< bs)
-    where g (CondBranch _ tb fb) = join $ catMaybes [Just $ extract tb, extract <$> fb]
+    where g (CondBranch _ tb fb) = concat $ catMaybes [Just $ extract tb, extract <$> fb]
 
 -- | Assign each shake @Verbosity@ level to a Cabal @Verbosity@ level.
 shakeVerbosityToCabalVerbosity :: Shake.Verbosity -> Distribution.Verbosity
 shakeVerbosityToCabalVerbosity Silent     = silent
-shakeVerbosityToCabalVerbosity Quiet      = normal
-shakeVerbosityToCabalVerbosity Normal     = normal
-shakeVerbosityToCabalVerbosity Loud       = verbose
-shakeVerbosityToCabalVerbosity Chatty     = verbose
+shakeVerbosityToCabalVerbosity Error      = normal
+shakeVerbosityToCabalVerbosity Warn       = normal
+shakeVerbosityToCabalVerbosity Info       = verbose
+shakeVerbosityToCabalVerbosity Verbose    = verbose
 shakeVerbosityToCabalVerbosity Diagnostic = deafening
 
 -- | Get cabal dependencies, respecting verbosity level given to
diff --git a/src/Development/Shake/Cabal/Oracles.hs b/src/Development/Shake/Cabal/Oracles.hs
--- a/src/Development/Shake/Cabal/Oracles.hs
+++ b/src/Development/Shake/Cabal/Oracles.hs
@@ -7,6 +7,7 @@
 -- causes previously valid code to not typecheck... ok
 module Development.Shake.Cabal.Oracles ( hsOracle
                                        , cabalOracle
+                                       , CabalOracle
                                        , HsCompiler (..)
                                        , CabalVersion (..)
                                        ) where
@@ -18,6 +19,8 @@
 import           Development.Shake
 import           GHC.Generics      (Generic)
 
+type CabalOracle = CabalVersion -> Action String
+
 -- | Use this for tracking 'HsCompiler'
 --
 -- @since 0.2.1.0
@@ -27,7 +30,7 @@
 -- | Use this to track the version of cabal globally available
 --
 -- @since 0.2.1.0
-cabalOracle :: Rules (CabalVersion -> Action String)
+cabalOracle :: Rules CabalOracle
 cabalOracle = addOracle $ \CabalVersion -> do
     (Stdout out) <- command [] "cabal" [ "--numeric-version"]
     pure out