diff --git a/build-constraints.yaml b/build-constraints.yaml
index 26a88851..e2868a5d 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1229,6 +1229,9 @@ packages:
         # https://github.com/fpco/stackage/issues/710
         - fsnotify < 0.2
 
+        # https://github.com/fpco/stackage/issues/715
+        - postgresql-libpq < 0.9.1
+
 # Package flags are applied to individual packages, and override the values of
 # global-flags
 package-flags: