diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index fe9a948ab0e..ea2bae651ba 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -3267,7 +3267,7 @@ timezone_str(PyDateTime_TimeZone *self)
         Py_INCREF(self->name);
         return self->name;
     }
-    if (self == PyDateTime_TimeZone_UTC ||
+    if ((PyObject *)self == PyDateTime_TimeZone_UTC ||
            (GET_TD_DAYS(self->offset) == 0 &&
             GET_TD_SECONDS(self->offset) == 0 &&
             GET_TD_MICROSECONDS(self->offset) == 0))