diff --git a/server/main.py b/server/main.py
index 970dbfe..3325429 100644
--- a/server/main.py
+++ b/server/main.py
@@ -5,11 +5,15 @@ import os
 
 import config
 
+from .http_handler import HTTPHandler
+
 
 log = logging.getLogger(__name__)
 
 
 def init_server_socket(server_handler):
+    assert server_handler == HTTPHandler, "Server handler isn't Handler type"
+
     try:
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as main_server_socket:
             main_server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)