diff --git a/test/ModelSpec.hs b/test/ModelSpec.hs
index fb383203c..66b90b480 100644
--- a/test/ModelSpec.hs
+++ b/test/ModelSpec.hs
@@ -198,10 +198,6 @@ instance Arbitrary VerpMode where
   arbitrary = genericArbitrary
   shrink = genericShrink
 
-instance Arbitrary StudyModule where
-  arbitrary = genericArbitrary
-  shrink = genericShrink
-
 
 spec :: Spec
 spec = do