diff --git a/src/core/suspend_.ml b/src/core/suspend_.ml
index cb4293a8..4d15ac77 100644
--- a/src/core/suspend_.ml
+++ b/src/core/suspend_.ml
@@ -1,4 +1,3 @@
-open Types_
 module A = Atomic_
 
 type suspension = unit Exn_bt.result -> unit