diff --git a/imperative/python/megengine/device.py b/imperative/python/megengine/device.py
index 9ba1c4d6..d9a8f2a7 100644
--- a/imperative/python/megengine/device.py
+++ b/imperative/python/megengine/device.py
@@ -50,7 +50,9 @@ _sh = _stream_helper()
 
 
 def _valid_device(inp):
-    if isinstance(inp, str) and re.match("^([cxg]pu|rocm)(\d+|\d+:\d+|x)$", inp):
+    if isinstance(inp, str) and re.match(
+        "^([cxg]pu|rocm|multithread)(\d+|\d+:\d+|x)$", inp
+    ):
         return True
     return False