diff --git a/build-constraints.yaml b/build-constraints.yaml
index f45104d5..5dfca150 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -764,6 +764,7 @@ packages:
         - foreign-store
         - formatting
         - gtk2hs-buildtools
+        - happy < 1.21.0 || > 1.21.0 # https://github.com/commercialhaskell/stackage/issues/6294
         - happy
         - hybrid-vectors
         - indents
@@ -6701,11 +6702,6 @@ packages:
       - stripe-wreq < 1.0.1.12
       - yaml < 0.11.7
 
-      # happy-1.21.0 is deprecated an unbuildable
-      # https://github.com/commercialhaskell/stackage/issues/6294
-      # see also https://github.com/commercialhaskell/stackage/issues/6242
-      - happy < 1.21
-
       # https://github.com/commercialhaskell/stackage/issues/6264
       # Requires GHC 9.2
       # Any new package-version that must use GHC 9.2 should be added here.