diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 789bf27bc4d..f282f998332 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -5053,8 +5053,10 @@ int fsconvert_strdup(PyObject *o, char**out)
         return 0;
     size = PyBytes_GET_SIZE(bytes);
     *out = PyMem_Malloc(size+1);
-    if (!*out)
+    if (!*out) {
+        PyErr_NoMemory();
         return 0;
+    }
     memcpy(*out, PyBytes_AsString(bytes), size+1);
     Py_DECREF(bytes);
     return 1;