diff --git a/src/kernel_internals/typing/infer_annotations.ml b/src/kernel_internals/typing/infer_annotations.ml
index b6f2e39f836b07024ebfa3d7c0ebc93b4c31c370..596454178f1dc4f5f0d0bdff2797570f30e33d0a 100644
--- a/src/kernel_internals/typing/infer_annotations.ml
+++ b/src/kernel_internals/typing/infer_annotations.ml
@@ -226,6 +226,7 @@ let populate_funspec_aux kf spec =
       let warn_if_not_builtin explicit_name name orig_name =
         if not (is_frama_c_builtin name) then
           Kernel.warning ~once:true ~current:true
+            ~wkey:Kernel.wkey_missing_spec
             "No code nor %s assigns clause for function %a, \
              generating default assigns from the %s"
             explicit_name Kernel_function.pretty kf orig_name