Use Py_ssize_t
diff --git a/Include/setobject.h b/Include/setobject.h
index cc93968..a16c2f7 100644
--- a/Include/setobject.h
+++ b/Include/setobject.h
@@ -35,14 +35,14 @@
 struct _setobject {
 	PyObject_HEAD
 
-	int fill;  /* # Active + # Dummy */
-	int used;  /* # Active */
+	Py_ssize_t fill;  /* # Active + # Dummy */
+	Py_ssize_t used;  /* # Active */
 
 	/* The table contains mask + 1 slots, and that's a power of 2.
 	 * We store the mask instead of the size because the mask is more
 	 * frequently needed.
 	 */
-	int mask;
+	Py_ssize_t mask;
 
 	/* table points to smalltable for small tables, else to
 	 * additional malloc'ed memory.  table is never NULL!  This rule