diff --git a/Python/ceval.c b/Python/ceval.c
index 8738470..298ad55 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -5039,6 +5039,8 @@
     if (nk != 0) {
         Py_ssize_t pos, i;
 
+        /* Issue #29318: Caller and callee functions must not share the
+           dictionary: kwargs must be copied. */
         kwtuple = PyTuple_New(2 * nk);
         if (kwtuple == NULL) {
             return NULL;