diff --git a/build-constraints.yaml b/build-constraints.yaml
index 482ffdb2..3ee22e7a 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1493,6 +1493,9 @@ packages:
         # https://github.com/fpco/stackage/issues/845
         - aeson < 0.10
 
+        # https://github.com/agocorona/MFlow/issues/64
+        - MFlow < 0.4.5.11
+
 # Package flags are applied to individual packages, and override the values of
 # global-flags
 package-flags: