diff --git a/pyinfra/server/server.py b/pyinfra/server/server.py
index 65d74c6..18c4bfb 100644
--- a/pyinfra/server/server.py
+++ b/pyinfra/server/server.py
@@ -79,4 +79,4 @@ def set_up_processing_server(process_fn):
 
 
 def valid(result):
-    return isinstance(result, dict) or isinstance(result, Nothing)
+    return isinstance(result, dict) or result is Nothing