diff --git a/socketio/handler.py b/socketio/handler.py
index 933cb64..8e3833f 100644
--- a/socketio/handler.py
+++ b/socketio/handler.py
@@ -213,7 +213,7 @@ def handle_bad_request(self):
         self.start_response("400 Bad Request", [
             ('Content-Type', 'text/plain'),
             ('Connection', 'close'),
-            ('Content-Length', 0)
+            ('Content-Length', '0')
         ])
 
 
@@ -222,5 +222,5 @@ def handle_disconnect_request(self):
         self.start_response("200 OK", [
             ('Content-Type', 'text/plain'),
             ('Connection', 'close'),
-            ('Content-Length', 0)
+            ('Content-Length', '0')
         ])