diff --git a/Misc/NEWS.d/next/Build/2025-08-27-09-52-45.gh-issue-138061.fMVS9w.rst b/Misc/NEWS.d/next/Build/2025-08-27-09-52-45.gh-issue-138061.fMVS9w.rst
new file mode 100644
index 00000000000000..7af79d0b87ef55
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2025-08-27-09-52-45.gh-issue-138061.fMVS9w.rst
@@ -0,0 +1 @@
+Ensure reproducible builds by making JIT stencil header generation deterministic.
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-07-09-21-27-14.gh-issue-132657.kSA8R3.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-09-21-27-14.gh-issue-132657.kSA8R3.rst
new file mode 100644
index 00000000000000..99f7a990875a0a
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-09-21-27-14.gh-issue-132657.kSA8R3.rst
@@ -0,0 +1 @@
+Improve performance of :class:`frozenset` by removing locks in the free-threading build.
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 63ce55e236546f..d8340499be5aae 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -86,6 +86,8 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
     int probes;
     int cmp;
 
+    int frozenset = PyFrozenSet_CheckExact(so);
+
     while (1) {
         entry = &so->table[i];
         probes = (i + LINEAR_PROBES <= mask) ? LINEAR_PROBES: 0;
@@ -102,13 +104,20 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
                     && unicode_eq(startkey, key))
                     return entry;
                 table = so->table;
-                Py_INCREF(startkey);
-                cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
-                Py_DECREF(startkey);
-                if (cmp < 0)
-                    return NULL;
-                if (table != so->table || entry->key != startkey)
-                    return set_lookkey(so, key, hash);
+                if (frozenset) {
+                    cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
+                    if (cmp < 0)
+                        return NULL;
+                } else {
+                    // incref startkey because it can be removed from the set by the compare
+                    Py_INCREF(startkey);
+                    cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
+                    Py_DECREF(startkey);
+                    if (cmp < 0)
+                        return NULL;
+                    if (table != so->table || entry->key != startkey)
+                        return set_lookkey(so, key, hash);
+                }
                 if (cmp > 0)
                     return entry;
                 mask = so->mask;
@@ -2235,10 +2244,16 @@ set_contains_lock_held(PySetObject *so, PyObject *key)
 int
 _PySet_Contains(PySetObject *so, PyObject *key)
 {
+    assert(so);
+
     int rv;
-    Py_BEGIN_CRITICAL_SECTION(so);
-    rv = set_contains_lock_held(so, key);
-    Py_END_CRITICAL_SECTION();
+    if (PyFrozenSet_CheckExact(so)) {
+        rv = set_contains_lock_held(so, key);
+    } else {
+        Py_BEGIN_CRITICAL_SECTION(so);
+        rv = set_contains_lock_held(so, key);
+        Py_END_CRITICAL_SECTION();
+    }
     return rv;
 }
 
diff --git a/Tools/jit/_targets.py b/Tools/jit/_targets.py
index 7e261c9f8e297f..c3ce24643fd4a6 100644
--- a/Tools/jit/_targets.py
+++ b/Tools/jit/_targets.py
@@ -71,6 +71,9 @@ def _compute_digest(self) -> str:
         hasher.update(PYTHON_EXECUTOR_CASES_C_H.read_bytes())
         hasher.update((self.pyconfig_dir / "pyconfig.h").read_bytes())
         for dirpath, _, filenames in sorted(os.walk(TOOLS_JIT)):
+            # Exclude cache files from digest computation to ensure reproducible builds.
+            if dirpath.endswith("__pycache__"):
+                continue
             for filename in filenames:
                 hasher.update(pathlib.Path(dirpath, filename).read_bytes())
         return hasher.hexdigest()