diff --git a/metagpt/utils/common.py b/metagpt/utils/common.py
index 509d355b6..d98e4522b 100644
--- a/metagpt/utils/common.py
+++ b/metagpt/utils/common.py
@@ -407,8 +407,8 @@ def concat_namespace(*args) -> str:
     return ":".join(str(value) for value in args)
 
 
-def split_namespace(ns_class_name: str) -> List[str]:
-    return ns_class_name.split(":", maxsplit=1)
+def split_namespace(ns_class_name: str, maxsplit=1) -> List[str]:
+    return ns_class_name.split(":", maxsplit=maxsplit)
 
 
 def general_after_log(i: "loguru.Logger", sec_format: str = "%0.3f") -> typing.Callable[["RetryCallState"], None]:
diff --git a/tests/metagpt/utils/test_common.py b/tests/metagpt/utils/test_common.py
index 9b1fa878e..b365f424f 100644
--- a/tests/metagpt/utils/test_common.py
+++ b/tests/metagpt/utils/test_common.py
@@ -178,7 +178,7 @@ class TestGetProjectRoot:
         ],
     )
     def test_split_namespace(self, val, want):
-        res = split_namespace(val)
+        res = split_namespace(val, maxsplit=-1)
         assert res == want
 
     def test_read_json_file(self):