msgpack · rsiemens · May 17, 2026
diff --git a/msgpack/fallback.py b/msgpack/fallback.py
@@ -52,8 +52,6 @@ def newlist_hint(size):
 TYPE_BIN = 4
 TYPE_EXT = 5

-DEFAULT_RECURSE_LIMIT = 511
-

 def _check_type_strict(obj, t, type=type, tuple=tuple):
    if type(t) is tuple:
@@ -682,7 +680,6 @@ def __init__(
    def _pack(
        self,
        obj,
-        nest_limit=DEFAULT_RECURSE_LIMIT,
        check=isinstance,
        check_type_strict=_check_type_strict,
    ):
@@ -693,8 +690,6 @@ def _pack(
        else:
            list_types = (list, tuple)
        while True:
-            if nest_limit < 0:
-                raise ValueError("recursion limit exceeded")
            if obj is None:
                return self._buffer.write(b"\xc0")
            if check(obj, bool):
@@ -783,10 +778,10 @@ def _pack(
                n = len(obj)
                self._pack_array_header(n)
                for i in range(n):
-                    self._pack(obj[i], nest_limit - 1)
+                    self._pack(obj[i])
                return
            if check(obj, dict):
-                return self._pack_map_pairs(len(obj), obj.items(), nest_limit - 1)
+                return self._pack_map_pairs(len(obj), obj.items())

            if self._datetime and check(obj, _DateTime) and obj.tzinfo is not None:
                obj = Timestamp.from_datetime(obj)
@@ -886,11 +881,11 @@ def _pack_map_header(self, n):
            return self._buffer.write(struct.pack(">BI", 0xDF, n))
        raise ValueError("Dict is too large")

-    def _pack_map_pairs(self, n, pairs, nest_limit=DEFAULT_RECURSE_LIMIT):
+    def _pack_map_pairs(self, n, pairs):
        self._pack_map_header(n)
        for k, v in pairs:
-            self._pack(k, nest_limit - 1)
-            self._pack(v, nest_limit - 1)
+            self._pack(k)
+            self._pack(v)

    def _pack_raw_header(self, n):
        if n <= 0x1F: