diff --git a/build-constraints.yaml b/build-constraints.yaml
index 2e200c96..3fa6a499 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1082,7 +1082,7 @@ packages:
 
         # Not a maintainer
         - arithmoi
-        #- folds
+        - folds
         - friendly-time
         - hashable
         - haxl
@@ -3133,6 +3133,8 @@ expected-test-failures:
     - cubicbezier # https://github.com/kuribas/cubicbezier/issues/3
 
     - yesod-auth-basic # https://github.com/creichert/yesod-auth-basic/issues/1
+
+    - folds # https://github.com/ekmett/folds/issues/12
 # end of expected-test-failures
 
 # Benchmarks which are known not to build. Note that, currently we do not run