diff --git a/class.c b/class.c
index 0acac96022..28743a229e 100644
--- a/class.c
+++ b/class.c
@@ -1353,7 +1353,7 @@ rb_prepend_module(VALUE klass, VALUE module)
     if (RB_TYPE_P(klass, T_MODULE)) {
         rb_subclass_entry_t *iclass = RCLASS_SUBCLASSES(klass);
         // skip the placeholder subclass entry at the head of the list if it exists
-        if (iclass && iclass->next) {
+        if (iclass) {
             RUBY_ASSERT(!iclass->klass);
             iclass = iclass->next;
         }