diff --git a/msgpack/fallback.py b/msgpack/fallback.py
index 5f624b8..4307bc8 100644
--- a/msgpack/fallback.py
+++ b/msgpack/fallback.py
@@ -529,7 +529,7 @@ class Unpacker:
                         raise ValueError("%s is not allowed for map key" % str(type(key)))
                     if isinstance(key, str):
                         key = sys.intern(key)
-                    if isinstance(key, list):
+                    elif isinstance(key, list):
                         key = tuple(key)
                     ret[key] = self._unpack(EX_CONSTRUCT)
                 if self._object_hook is not None:
diff --git a/msgpack/unpack.h b/msgpack/unpack.h
index 4bd5fc4..28a0b04 100644
--- a/msgpack/unpack.h
+++ b/msgpack/unpack.h
@@ -198,8 +198,7 @@ static inline int unpack_callback_map_item(unpack_user* u, unsigned int current,
     }
     if (PyUnicode_CheckExact(k)) {
         PyUnicode_InternInPlace(&k);
-    }
-    if (PyList_CheckExact(k)) {
+    } else if (PyList_CheckExact(k)) {
         Py_ssize_t list_size = PyList_Size(k);
         PyObject* tuple = PyTuple_New(list_size);