1 files changed, 3 insertions, 0 deletions
diff --git a/class.c b/class.c
index d0ff92b6eb..0cee5caae2 100644
--- a/class.c
+++ b/class.c
@@ -659,6 +659,9 @@ rb_define_class(const char *name, VALUE super)
 	if (rb_class_real(RCLASS_SUPER(klass)) != super) {
 	    rb_raise(rb_eTypeError, "superclass mismatch for class %s", name);
 	}
+
+        /* Class may have been defined in Ruby and not pin-rooted */
+        rb_vm_add_root_module(id, klass);
 	return klass;
     }
     if (!super) {