diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 1b7fe71186a163..63403795569a78 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -200,7 +200,7 @@ convert_fds_to_keep_to_c(PyObject *py_fds_to_keep, int *c_fds_to_keep)
     for (i = 0; i < len; ++i) {
         PyObject* fdobj = PyTuple_GET_ITEM(py_fds_to_keep, i);
         long fd = PyLong_AsLong(fdobj);
-        if (PyErr_Occurred()) {
+        if (fd == -1 && PyErr_Occurred()) {
             return -1;
         }
         if (fd < 0 || fd > INT_MAX) {