diff --git a/cabal.ghcjs.project b/cabal.ghcjs.project
index 11ceb957..72902332 100644
--- a/cabal.ghcjs.project
+++ b/cabal.ghcjs.project
@@ -7,3 +7,5 @@ packages:
 -- we need to tell cabal we are using GHCJS
 compiler: ghcjs
 tests: True
+
+constraints: hashable <=1.3.3.0