diff --git a/Objects/namespaceobject.c b/Objects/namespaceobject.c
index 7de102e..c2f9d30 100644
--- a/Objects/namespaceobject.c
+++ b/Objects/namespaceobject.c
@@ -103,15 +103,15 @@
             PyObject *value, *item;
 
             value = PyDict_GetItem(d, key);
-            assert(value != NULL);
-
-            item = PyUnicode_FromFormat("%S=%R", key, value);
-            if (item == NULL) {
-                loop_error = 1;
-            }
-            else {
-                loop_error = PyList_Append(pairs, item);
-                Py_DECREF(item);
+            if (value != NULL) {
+                item = PyUnicode_FromFormat("%S=%R", key, value);
+                if (item == NULL) {
+                    loop_error = 1;
+                }
+                else {
+                    loop_error = PyList_Append(pairs, item);
+                    Py_DECREF(item);
+                }
             }
         }