diff --git a/build-constraints.yaml b/build-constraints.yaml
index abf13c51..7b2971ee 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -386,6 +386,7 @@ packages:
         - pipes-concurrency
         - pipes-safe
         - turtle
+        - foldl
 
     "Chris Allen <cma@bitemyapp.com>":
         - bloodhound