diff --git a/build-constraints.yaml b/build-constraints.yaml
index 063f634d..fc577c60 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1156,9 +1156,6 @@ packages:
         # https://github.com/gtk2hs/gtk2hs/issues/109
         - gtk < 0.13.8
 
-        # https://github.com/fpco/stackage/issues/646
-        - clock < 0.5
-
         # https://github.com/fpco/stackage/issues/653
         - base-orphans < 0.4