1 files changed, 3 insertions, 0 deletions
diff --git a/variable.c b/variable.c
index 77c1c37240..76c0939c46 100644
--- a/variable.c
+++ b/variable.c
@@ -1548,6 +1548,9 @@ rb_define_const(klass, name, val)
 {
     ID id = rb_intern(name);
 
+    if (!rb_is_const_id(id)) {
+	rb_warn("rb_define_const: invalide name `%s' for constant", name);
+    }
     if (klass == rb_cObject) {
 	rb_secure(4);
     }