diff --git a/Objects/dictobject.c b/Objects/dictobject.c
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -360,7 +360,8 @@
     PyDictKeyEntry *entries = &keys->dk_entries[0];
     Py_ssize_t i, n;
     for (i = 0, n = DK_SIZE(keys); i < n; i++) {
-        Py_XDECREF(entries[i].me_key);
+        if (entries[i].me_key != dummy)
+            Py_XDECREF(entries[i].me_key);
         Py_XDECREF(entries[i].me_value);
     }
     PyMem_FREE(keys);
@@ -839,7 +840,6 @@
                 Py_INCREF(key);
                 ep->me_key = key;
                 ep->me_hash = hash;
-                Py_DECREF(dummy);
             } else {
                 assert(_PyDict_HasSplitTable(mp));
             }
@@ -966,13 +966,6 @@
     }
     else {
         assert(oldkeys->dk_lookup != lookdict_split);
-        if (oldkeys->dk_lookup != lookdict_unicode_nodummy) {
-            PyDictKeyEntry *ep0 = &oldkeys->dk_entries[0];
-            for (i = 0; i < oldsize; i++) {
-                if (ep0[i].me_key == dummy)
-                    Py_DECREF(dummy);
-            }
-        }
         assert(oldkeys->dk_refcnt == 1);
         DK_DEBUG_DECREF PyMem_FREE(oldkeys);
     }
@@ -1236,7 +1229,6 @@
     if (!_PyDict_HasSplitTable(mp)) {
         ENSURE_ALLOWS_DELETIONS(mp);
         old_key = ep->me_key;
-        Py_INCREF(dummy);
         ep->me_key = dummy;
         Py_DECREF(old_key);
     }