diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+#### 0.17.0.5
+
+* Allow `aeson 0.9.*`
+
 #### 0.17.0.4
 
 * Allow `rest-core 0.36.*`
diff --git a/rest-gen.cabal b/rest-gen.cabal
--- a/rest-gen.cabal
+++ b/rest-gen.cabal
@@ -1,5 +1,5 @@
 name:                rest-gen
-version:             0.17.0.4
+version:             0.17.0.5
 description:         Documentation and client generation from rest definition.
 synopsis:            Documentation and client generation from rest definition.
 maintainer:          code@silk.co
@@ -50,7 +50,7 @@
       base >= 4.5 && < 4.9
     , Cabal >= 1.16 && < 1.23
     , HStringTemplate >= 0.6 && < 0.9
-    , aeson >= 0.7 && < 0.9
+    , aeson >= 0.7 && < 0.10
     , blaze-html >= 0.5 && < 0.9
     , code-builder == 0.1.*
     , directory >= 1.1 && < 1.3
@@ -67,11 +67,12 @@
     , semigroups >= 0.5.0 && < 0.17
     , scientific >= 0.3.2 && < 0.4
     , split >= 0.1 && < 0.3
-    , tagged >= 0.2 && < 0.9
     , text >= 0.11 && < 1.3
     , uniplate >= 1.6.12 && < 1.7
     , unordered-containers == 0.2.*
     , vector == 0.10.*
+  if impl(ghc < 7.8)
+    build-depends: tagged >= 0.2 && < 0.9
 
 test-suite rest-gen-tests
   hs-source-dirs:    tests
@@ -83,7 +84,7 @@
     , HUnit == 1.2.*
     , fclabels >= 1.0.4 && < 2.1
     , haskell-src-exts >= 1.15.0 && < 1.17
-    , rest-core == 0.35.*
+    , rest-core >= 0.35 && < 0.37
     , rest-gen
     , test-framework == 0.8.*
     , test-framework-hunit == 0.3.*