diff --git a/port_config.py b/port_config.py
index d9ab62f..2f78df1 100644
--- a/port_config.py
+++ b/port_config.py
@@ -10,5 +10,5 @@ Author: Jeffrey Tsai
 """
 
 # Server configuration
-SERVER_HOST = "0.0.0.0"  # Bind to all interfaces instead of just localhost
+SERVER_HOST = "127.0.0.1"  # Bind to localhost for security
 SERVER_PORT = 4550         # Use port 4550 as in the original configuration