diff --git a/Include/cpython/dictobject.h b/Include/cpython/dictobject.h
index ac422264ae3a2f..b113c7fdcf6515 100644
--- a/Include/cpython/dictobject.h
+++ b/Include/cpython/dictobject.h
@@ -18,7 +18,7 @@ typedef struct {
      * Bits 0-7 are for dict watchers.
      * Bits 8-11 are for the watched mutation counter (used by tier2 optimization)
      * The remaining bits are not currently used. */
-    uint64_t ma_watcher_tag;
+    uint64_t _ma_watcher_tag;
 
     PyDictKeysObject *ma_keys;
 
diff --git a/Include/internal/pycore_dict.h b/Include/internal/pycore_dict.h
index a4f57697e0a41c..1920724c1d4f57 100644
--- a/Include/internal/pycore_dict.h
+++ b/Include/internal/pycore_dict.h
@@ -246,7 +246,7 @@ _PyDict_NotifyEvent(PyInterpreterState *interp,
                     PyObject *value)
 {
     assert(Py_REFCNT((PyObject*)mp) > 0);
-    int watcher_bits = mp->ma_watcher_tag & DICT_WATCHER_MASK;
+    int watcher_bits = mp->_ma_watcher_tag & DICT_WATCHER_MASK;
     if (watcher_bits) {
         RARE_EVENT_STAT_INC(watched_dict_modification);
         _PyDict_SendEvent(watcher_bits, event, mp, key, value);
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 3842ed82c632d2..594468d054bbb3 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -877,7 +877,7 @@ new_dict(PyInterpreterState *interp,
     mp->ma_keys = keys;
     mp->ma_values = values;
     mp->ma_used = used;
-    mp->ma_watcher_tag = 0;
+    mp->_ma_watcher_tag = 0;
     ASSERT_CONSISTENT(mp);
     return (PyObject *)mp;
 }
@@ -3966,7 +3966,7 @@ copy_lock_held(PyObject *o)
         split_copy->ma_values = newvalues;
         split_copy->ma_keys = mp->ma_keys;
         split_copy->ma_used = mp->ma_used;
-        split_copy->ma_watcher_tag = 0;
+        split_copy->_ma_watcher_tag = 0;
         dictkeys_incref(mp->ma_keys);
         if (_PyObject_GC_IS_TRACKED(mp))
             _PyObject_GC_TRACK(split_copy);
@@ -4739,7 +4739,7 @@ dict_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     PyDictObject *d = (PyDictObject *)self;
 
     d->ma_used = 0;
-    d->ma_watcher_tag = 0;
+    d->_ma_watcher_tag = 0;
     dictkeys_incref(Py_EMPTY_KEYS);
     d->ma_keys = Py_EMPTY_KEYS;
     d->ma_values = NULL;
@@ -7356,7 +7356,7 @@ PyDict_Watch(int watcher_id, PyObject* dict)
     if (validate_watcher_id(interp, watcher_id)) {
         return -1;
     }
-    ((PyDictObject*)dict)->ma_watcher_tag |= (1LL << watcher_id);
+    ((PyDictObject*)dict)->_ma_watcher_tag |= (1LL << watcher_id);
     return 0;
 }
 
@@ -7371,7 +7371,7 @@ PyDict_Unwatch(int watcher_id, PyObject* dict)
     if (validate_watcher_id(interp, watcher_id)) {
         return -1;
     }
-    ((PyDictObject*)dict)->ma_watcher_tag &= ~(1LL << watcher_id);
+    ((PyDictObject*)dict)->_ma_watcher_tag &= ~(1LL << watcher_id);
     return 0;
 }
 
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index c5a94a45437b3a..f30e873605d858 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -56,14 +56,14 @@ static int
 get_mutations(PyObject* dict) {
     assert(PyDict_CheckExact(dict));
     PyDictObject *d = (PyDictObject *)dict;
-    return (d->ma_watcher_tag >> DICT_MAX_WATCHERS) & ((1 << DICT_WATCHED_MUTATION_BITS)-1);
+    return (d->_ma_watcher_tag >> DICT_MAX_WATCHERS) & ((1 << DICT_WATCHED_MUTATION_BITS)-1);
 }
 
 static void
 increment_mutations(PyObject* dict) {
     assert(PyDict_CheckExact(dict));
     PyDictObject *d = (PyDictObject *)dict;
-    d->ma_watcher_tag += (1 << DICT_MAX_WATCHERS);
+    d->_ma_watcher_tag += (1 << DICT_MAX_WATCHERS);
 }
 
 /* The first two dict watcher IDs are reserved for CPython,