diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-06-08-13-14-42.gh-issue-150902.-CWZ66.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-06-08-13-14-42.gh-issue-150902.-CWZ66.rst
new file mode 100644
index 000000000000000..e3b7cd387b439fe
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-06-08-13-14-42.gh-issue-150902.-CWZ66.rst
@@ -0,0 +1 @@
+Apply an existing optimization of PyCriticalSection (single mutex) to PyCriticalSection2: avoid acquiring the same locks that the current CS has already acquired.
diff --git a/Python/critical_section.c b/Python/critical_section.c
index 98e23eda7cdd77e..a2673f51fe73180 100644
--- a/Python/critical_section.c
+++ b/Python/critical_section.c
@@ -72,6 +72,21 @@ _PyCriticalSection2_BeginSlow(PyThreadState *tstate, PyCriticalSection2 *c, PyMu
         c->_cs_base._cs_prev = 0;
         return;
     }
+    // Same optimization as in _PyCriticalSection_BeginSlow: skip locking when
+    // recursively acquiring the same locks.
+    if (tstate->critical_section &&
+        tstate->critical_section & _Py_CRITICAL_SECTION_TWO_MUTEXES) {
+        PyCriticalSection2 *prev2 = (PyCriticalSection2 *)
+            untag_critical_section(tstate->critical_section);
+        assert(m1 < m2);
+        assert(prev2->_cs_base._cs_mutex < prev2->_cs_mutex2);
+        if (prev2->_cs_base._cs_mutex == m1 && prev2->_cs_mutex2 == m2) {
+            c->_cs_base._cs_mutex = NULL;
+            c->_cs_mutex2 = NULL;
+            c->_cs_base._cs_prev = 0;
+            return;
+        }
+    }
     c->_cs_base._cs_mutex = NULL;
     c->_cs_mutex2 = NULL;
     c->_cs_base._cs_prev = tstate->critical_section;