diff --git a/build-constraints.yaml b/build-constraints.yaml
index 68c9b8c4..c59a0d4f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3272,6 +3272,9 @@ packages:
         - hledger-ui < 1.3
         - hledger-web < 1.3
 
+        # https://github.com/fpco/stackage/issues/2631
+        - protocol-buffers == 2.4.0
+        
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of