diff --git a/build-constraints.yaml b/build-constraints.yaml
index b9f7a423..56000712 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -6990,10 +6990,6 @@ package-flags:
         ghc_7_7: false
         ghc_8_0: true
 
-    # https://github.com/commercialhaskell/stackage/issues/3666 and 3667
-    exinst:
-        serialise: false
-
     functor-classes-compat:
         containers: true