diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 01e5c72..c4e73eb 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -8304,7 +8304,7 @@
                 goto Undefined;
             if (value < 0 || value > MAX_UNICODE) {
                 PyErr_Format(PyExc_TypeError,
-                             "character mapping must be in range(0x%lx)",
+                             "character mapping must be in range(0x%x)",
                              (unsigned long)MAX_UNICODE + 1);
                 goto onError;
             }