diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -367,10 +378,13 @@ module_repr(PyModuleObject *m)
 static int
 module_traverse(PyModuleObject *m, visitproc visit, void *arg)
 {
-    if (m->md_def && m->md_def->m_traverse) {
-        int res = m->md_def->m_traverse((PyObject*)m, visit, arg);
-        if (res)
-            return res;
+    if (m->md_def) {
+        if (m->md_def->m_traverse) {
+            int res = m->md_def->m_traverse((PyObject*)m, visit, arg);
+            if (res)
+                return res;
+        }
+        Py_VISIT(m->md_def->m_base.m_copy);
     }
     Py_VISIT(m->md_dict);
     return 0;
@@ -379,10 +393,13 @@ module_traverse(PyModuleObject *m, visitproc visit, void *arg)
 static int
 module_clear(PyModuleObject *m)
 {
-    if (m->md_def && m->md_def->m_clear) {
-        int res = m->md_def->m_clear((PyObject*)m);
-        if (res)
-            return res;
+    if (m->md_def) {
+        if (m->md_def->m_clear) {
+            int res = m->md_def->m_clear((PyObject*)m);
+            if (res)
+                return res;
+        }
+        Py_CLEAR(m->md_def->m_base.m_copy);
     }
     Py_CLEAR(m->md_dict);
     return 0;