diff --git a/Objects/setobject.c b/Objects/setobject.c
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -300,9 +300,10 @@
             memcpy(small_copy, oldtable, sizeof(small_copy));
             oldtable = small_copy;
         }
+        memset(newtable, 0, sizeof(setentry) * PySet_MINSIZE);
     }
     else {
-        newtable = PyMem_NEW(setentry, newsize);
+        newtable = PyMem_Calloc(newsize, sizeof(setentry));
         if (newtable == NULL) {
             PyErr_NoMemory();
             return -1;
@@ -313,7 +314,6 @@
     assert(newtable != oldtable);
     so->table = newtable;
     so->mask = newsize - 1;
-    memset(newtable, 0, sizeof(setentry) * newsize);
     i = so->used;
     so->used = 0;
     so->fill = 0;