diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-04-08-02-49-07.gh-issue-148189.0KpXID.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-08-02-49-07.gh-issue-148189.0KpXID.rst
new file mode 100644
index 00000000000000..d90e30b3d3fba8
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-08-02-49-07.gh-issue-148189.0KpXID.rst
@@ -0,0 +1 @@
+Repaired undercount of bytes in type-specific free lists reported by sys._debugmallocstats(). For types that participate in cyclic garbage collection, it was missing two pointers used by GC.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 67bc4319e0bae2..fc8f3a6209698b 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -443,7 +443,7 @@ _PyDict_DebugMallocStats(FILE *out)
 {
     _PyDebugAllocatorStats(out, "free PyDictObject",
                            _Py_FREELIST_SIZE(dicts),
-                           sizeof(PyDictObject));
+                           _PyType_PreHeaderSize(&PyDict_Type) + sizeof(PyDictObject));
     _PyDebugAllocatorStats(out, "free PyDictKeysObject",
                            _Py_FREELIST_SIZE(dictkeys),
                            sizeof(PyDictKeysObject));
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 5c9fd55bab1b22..2e53a440584786 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -234,7 +234,7 @@ _PyList_DebugMallocStats(FILE *out)
     _PyDebugAllocatorStats(out,
                            "free PyListObject",
                             _Py_FREELIST_SIZE(lists),
-                           sizeof(PyListObject));
+                           _PyType_PreHeaderSize(&PyList_Type) + sizeof(PyListObject));
 }
 
 PyObject *