diff --git a/build-constraints.yaml b/build-constraints.yaml
index 82aae766..cb549b44 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4473,6 +4473,9 @@ packages:
         # https://github.com/commercialhaskell/stackage/issues/4053
         - yaml < 0.11
 
+        # https://github.com/commercialhaskell/stackage/issues/4056
+        - postgresql-simple < 0.6
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of