diff --git a/Modules/_sre.c b/Modules/_sre.c
index b98f6e6..839763d 100644
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -1376,13 +1376,10 @@
 LOCAL(void)
 state_reset(SRE_STATE* state)
 {
-    int i;
-
     state->lastmark = 0;
 
     /* FIXME: dynamic! */
-    for (i = 0; i < SRE_MARK_SIZE; i++)
-        state->mark[i] = NULL;
+    memset(state->mark, 0, sizeof(*state->mark) * SRE_MARK_SIZE);
 
     state->lastindex = -1;
 
diff --git a/Objects/listobject.c b/Objects/listobject.c
index f29774e..78cc679 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -56,7 +56,6 @@
 PyObject *
 PyList_New(int size)
 {
-	int i;
 	PyListObject *op;
 	size_t nbytes;
 	if (size < 0) {
@@ -80,10 +79,9 @@
 		if (op->ob_item == NULL) {
 			return PyErr_NoMemory();
 		}
+		memset(op->ob_item, 0, sizeof(*op->ob_item) * size);
 	}
 	op->ob_size = size;
-	for (i = 0; i < size; i++)
-		op->ob_item[i] = NULL;
 	_PyObject_GC_TRACK(op);
 	return (PyObject *) op;
 }
@@ -1576,8 +1574,7 @@
 		PyErr_NoMemory();
 		goto error;
 	}
-	for (i = 0; i < n; i++)
-		result->ob_item[i] = NULL;
+	memset(result->ob_item, 0, sizeof(*result->ob_item) * n);
 	result->ob_size = n;
 
 	/* Run iterator to exhaustion. */
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index a207102..525e8f6 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -26,7 +26,6 @@
 PyObject *
 PyTuple_New(register int size)
 {
-	register int i;
 	register PyTupleObject *op;
 	if (size < 0) {
 		PyErr_BadInternalCall();
@@ -71,8 +70,7 @@
 		if (op == NULL)
 			return NULL;
 	}
-	for (i = 0; i < size; i++)
-		op->ob_item[i] = NULL;
+	memset(op->ob_item, 0, sizeof(*op->ob_item) * size);
 #if MAXSAVESIZE > 0
 	if (size == 0) {
 		free_tuples[0] = op;
@@ -697,8 +695,9 @@
 	}
 	_Py_NewReference((PyObject *) sv);
 	/* Zero out items added by growing */
-	for (i = oldsize; i < newsize; i++)
-		sv->ob_item[i] = NULL;
+	if (newsize > oldsize)
+		memset(sv->ob_item, 0,
+			sizeof(*sv->ob_item) * (newsize - oldsize));
 	*pv = (PyObject *) sv;
 	_PyObject_GC_TRACK(sv);
 	return 0;