1 files changed, 1 insertions, 1 deletions
diff --git a/Modules/fcntlmodule.c b/Modules/fcntlmodule.c
index cf0ac19976..56e40212d1 100644
--- a/Modules/fcntlmodule.c
+++ b/Modules/fcntlmodule.c
@@ -42,7 +42,7 @@ fcntl_fcntl(PyObject *self, PyObject *args)
 
     if (PyArg_ParseTuple(args, "O&is#:fcntl",
                          conv_descriptor, &fd, &code, &str, &len)) {
-        if (len > sizeof buf) {
+        if ((size_t)len > sizeof buf) {
             PyErr_SetString(PyExc_ValueError,
                             "fcntl string arg too long");
             return NULL;