diff --git a/src/core/CCListLabels.ml b/src/core/CCListLabels.ml
index e2f676b6..282134b4 100644
--- a/src/core/CCListLabels.ml
+++ b/src/core/CCListLabels.ml
@@ -2,3 +2,17 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
 include CCList
+
+(*$inject
+  module type L = module type of CCList
+  module type LL = module type of CCListLabels
+*)
+
+(*$R
+  ignore (module CCListLabels : L)
+*)
+
+(*$R
+  ignore (module CCList : LL)
+*)
+