diff --git a/test/FoundationSpec.hs b/test/FoundationSpec.hs
index 45080259b..f44875286 100644
--- a/test/FoundationSpec.hs
+++ b/test/FoundationSpec.hs
@@ -105,6 +105,10 @@ instance Arbitrary SchoolWorkflowWorkflowR where
   arbitrary = genericArbitrary
   shrink = genericShrink
 
+instance Arbitrary AMatchingR where
+  arbitrary = genericArbitrary
+  shrink = genericShrink
+
 instance Arbitrary (Route UniWorX) where
   arbitrary = genericArbitrary
   shrink = genericShrink