diff --git a/Lib/functools.py b/Lib/functools.py
index 9d53d3601559b2..c42f608c38be6c 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -326,6 +326,10 @@ def _partial_new(cls, func, /, *args, **keywords):
                             "or a descriptor")
     if args and args[-1] is Placeholder:
         raise TypeError("trailing Placeholders are not allowed")
+    if keywords:
+        for v in keywords.values():
+            if v is Placeholder:
+                raise TypeError("keyword Placeholders are not allowed")
     if isinstance(func, base_cls):
         pto_phcount = func._phcount
         tot_args = func.args
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index bdaa9a7ec4f020..5d937424218c2a 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -249,6 +249,12 @@ def test_placeholders_optimization(self):
         self.assertEqual(p2.args, (PH, 0))
         self.assertEqual(p2(1), ((1, 0), {}))
 
+    def test_placeholders_kw_restriction(self):
+        PH = self.module.Placeholder
+        exc_string = 'keyword Placeholders are not allowed'
+        with self.assertRaisesRegex(TypeError, exc_string):
+            self.partial(capture, a=PH)
+
     def test_construct_placeholder_singleton(self):
         PH = self.module.Placeholder
         tp = type(PH)
diff --git a/Misc/NEWS.d/next/Library/2024-10-09-15-16-09.gh-issue-125028.IOzxPL.rst b/Misc/NEWS.d/next/Library/2024-10-09-15-16-09.gh-issue-125028.IOzxPL.rst
new file mode 100644
index 00000000000000..8320d6b6c10a1d
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-10-09-15-16-09.gh-issue-125028.IOzxPL.rst
@@ -0,0 +1 @@
+:data:`functools.Placeholder` is not allowed in :func:`functools.partial` keyword vaules.
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
index 802b1cf792c555..dc5e4229670797 100644
--- a/Modules/_functoolsmodule.c
+++ b/Modules/_functoolsmodule.c
@@ -280,30 +280,33 @@ partial_new(PyTypeObject *type, PyObject *args, PyObject *kw)
         assert(PyTuple_Check(pto->args));
     }
 
+    /* process keywords */
     if (pto_kw == NULL || PyDict_GET_SIZE(pto_kw) == 0) {
-        if (kw == NULL) {
-            pto->kw = PyDict_New();
-        }
-        else if (Py_REFCNT(kw) == 1) {
-            pto->kw = Py_NewRef(kw);
-        }
-        else {
-            pto->kw = PyDict_Copy(kw);
-        }
+        pto->kw = PyDict_New();
     }
     else {
         pto->kw = PyDict_Copy(pto_kw);
-        if (kw != NULL && pto->kw != NULL) {
-            if (PyDict_Merge(pto->kw, kw, 1) != 0) {
-                Py_DECREF(pto);
-                return NULL;
-            }
-        }
     }
     if (pto->kw == NULL) {
         Py_DECREF(pto);
         return NULL;
     }
+    if (kw != NULL) {
+        PyObject *key, *val;
+        Py_ssize_t pos = 0;
+        while (PyDict_Next(kw, &pos, &key, &val)) {
+            if (val == phold) {
+                Py_DECREF(pto);
+                PyErr_SetString(PyExc_TypeError,
+                                "keyword Placeholders are not allowed");
+                return NULL;
+            }
+            if (PyDict_SetItem(pto->kw, key, val)) {
+                Py_DECREF(pto);
+                return NULL;
+            }
+        }
+    }
 
     partial_setvectorcall(pto);
     return (PyObject *)pto;