diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index d7ec73031db..145d5b62918 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -487,6 +487,7 @@ test_u_code(PyObject *self)
 	/* issue4122: Undefined reference to _Py_ascii_whitespace on Windows */
 	/* Just use the macro and check that it compiles */
 	int x = Py_UNICODE_ISSPACE(25);
+	x = x;
 
         tuple = PyTuple_New(1);
         if (tuple == NULL)