diff --git a/build-constraints.yaml b/build-constraints.yaml
index 849345ce..152de22f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1656,6 +1656,7 @@ packages:
 
         # https://github.com/fpco/stackage/issues/946
         - cereal < 0.5
+        - messagepack-rpc < 0.5.1
 
 
 # end of packages