diff --git a/Include/pyport.h b/Include/pyport.h
index df97b99..9b5c54d 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -124,7 +124,9 @@
  * Py_ssize_t on the platform.
  */
 #ifndef PY_FORMAT_SIZE_T
-#   if SIZEOF_SIZE_T == SIZEOF_LONG
+#   if SIZEOF_SIZE_T == SIZEOF_INT
+#       define PY_FORMAT_SIZE_T ""
+#   elif SIZEOF_SIZE_T == SIZEOF_LONG
 #       define PY_FORMAT_SIZE_T "l"
 #   elif defined(MS_WINDOWS)
 #       define PY_FORMAT_SIZE_T "I"