diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 82bfb14..d6dcffd 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -670,7 +670,7 @@
 		return NULL;
 	}
 	if (((dequeobject *)deque)->maxlen != -1)
-		fmt = PyString_FromFormat("deque(%%r, maxlen=%" PY_FORMAT_SIZE_T "i)", 
+		fmt = PyString_FromFormat("deque(%%r, maxlen=%" PY_FORMAT_SIZE_T "d)", 
 					((dequeobject *)deque)->maxlen);
 	else
 		fmt = PyString_FromString("deque(%r)");