diff --git a/Objects/setobject.c b/Objects/setobject.c
index fbac596..83bff81 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -223,9 +223,13 @@
     entry->hash = hash;
     if ((size_t)so->fill*3 < mask*2)
         return 0;
-    return set_table_resize(so, so->used);
+    if (!set_table_resize(so, so->used))
+        return 0;
+    Py_INCREF(key);
+    return -1;
 
   found_active:
+    Py_DECREF(key);
     return 0;
 }