diff --git a/build-constraints.yaml b/build-constraints.yaml
index 89980995..7ae412ad 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -7963,6 +7963,7 @@ packages:
 
         # https://github.com/commercialhaskell/stackage/issues/7638
         - gi-gdk < 4.0.10
+        - gi-gdkx11 < 4.0.9
         - gi-gsk < 4.0.9
         - gi-gtk < 4.0.12
     # end of Stackage upper bounds