diff --git a/Python/traceback.c b/Python/traceback.c
index 63ecc3c..42bbd53 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -171,7 +171,7 @@
 		if (!PyUnicode_Check(v))
 			continue;
 		path = _PyUnicode_AsStringAndSize(v, &len);
-		if (len + 1 + taillen >= (Py_ssize_t)namelen - 1)
+		if (len + 1 + (Py_ssize_t)taillen >= (Py_ssize_t)namelen - 1)
 			continue; /* Too long */
 		strcpy(namebuf, path);
 		if (strlen(namebuf) != len)