diff --git a/build-constraints.yaml b/build-constraints.yaml
index 4bf5099e..a2bd196a 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -10,7 +10,8 @@ packages:
         - conduit-combinators
         - conduit-extra
         - hebrew-time
-        - keter
+        # https://github.com/fpco/stackage/issues/717
+        - keter < 0.4.3
         - markdown
         - mime-mail
         - mime-mail-ses