diff --git a/Modules/grpmodule.c b/Modules/grpmodule.c
index 29da9936b65504..e71f4ea8cb6b45 100644
--- a/Modules/grpmodule.c
+++ b/Modules/grpmodule.c
@@ -7,6 +7,8 @@
 
 #include "Python.h"
 #include "posixmodule.h"
+#include "pycore_list.h"          // _PyList_AppendTakeRef()
+#include "pycore_object.h"        // _PyObject_IsUniquelyReferenced()
 
 #include <errno.h>                // ERANGE
 #include <grp.h>                  // getgrgid_r()
@@ -290,18 +292,19 @@ grp_getgrall_impl(PyObject *module)
     setgrent();
 
     struct group *p;
+    // `d` is a local list; append items without a lock using
+    // _PyList_AppendTakeRef() within the loop.
+    assert(_PyObject_IsUniquelyReferenced(d));
     while ((p = getgrent()) != NULL) {
         // gh-126316: Don't release the mutex around mkgrent() since
         // setgrent()/endgrent() are not reentrant / thread-safe. A deadlock
         // is unlikely since mkgrent() should not be able to call arbitrary
         // Python code.
         PyObject *v = mkgrent(module, p);
-        if (v == NULL || PyList_Append(d, v) != 0) {
-            Py_XDECREF(v);
+        if (v == NULL || _PyList_AppendTakeRef((PyListObject *)d, v) != 0) {
             Py_CLEAR(d);
             goto done;
         }
-        Py_DECREF(v);
     }
 
 done: