diff --git a/github-tools.cabal b/github-tools.cabal
index 1aa408c..6884a3b 100644
--- a/github-tools.cabal
+++ b/github-tools.cabal
@@ -115,7 +115,7 @@ library
   default-language:    Haskell2010
   build-depends:
       base >= 4 && < 5
-    , aeson             >= 0.8.1.0
+    , aeson             >= 0.8.1.0 && < 2
     , bytestring
     , containers
     , cryptohash