diff --git a/build-constraints.yaml b/build-constraints.yaml
index b6381a27..2177f81f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2040,6 +2040,9 @@ packages:
 
         # https://github.com/fpco/stackage/issues/1265
         - brick < 0.5
+
+        # https://github.com/fpco/stackage/issues/1266
+        - transformers-compat < 0.5
 # end of packages