diff --git a/Dockerfile b/Dockerfile
index e0f6f9a..eb269cb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,7 +24,7 @@ RUN useradd -m shellmate && \
 USER shellmate
 RUN ssh-keygen -t ed25519 -f /etc/shellmate/ssh_host_key -N ""
 
-EXPOSE 2222
+EXPOSE 22
 
 ENV STOCKFISH_PATH=/usr/games/stockfish
 
diff --git a/docker-compose.yml b/docker-compose.yml
index 958239e..9e14dc7 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,9 +2,9 @@ services:
   shellmate:
     build: .
     ports:
-      - "2222:2222"
+      - "22:22"
     environment:
-      - SHELLMATE_SSH_PORT=2222
+      - SHELLMATE_SSH_PORT=22
       - SHELLMATE_REDIS_URL=redis://redis:6379
       - SHELLMATE_DATABASE_URL=postgresql://shellmate:shellmate@postgres:5432/shellmate
       - STOCKFISH_PATH=/usr/games/stockfish
@@ -13,7 +13,7 @@ services:
       - postgres
     restart: unless-stopped
     healthcheck:
-      test: ["CMD", "nc", "-z", "localhost", "2222"]
+      test: ["CMD", "nc", "-z", "localhost", "22"]
       interval: 30s
       timeout: 10s
       retries: 3
diff --git a/src/shellmate/ssh/server.py b/src/shellmate/ssh/server.py
index 0997180..6c48948 100644
--- a/src/shellmate/ssh/server.py
+++ b/src/shellmate/ssh/server.py
@@ -90,6 +90,9 @@ async def run_simple_menu(process, username: str, mode: str, width: int, height:
         def __init__(self, proc):
             self._proc = proc
         def write(self, data):
+            # Encode string to bytes for binary mode SSH
+            if isinstance(data, str):
+                data = data.encode('utf-8')
             self._proc.stdout.write(data)
         def flush(self):
             pass
@@ -250,10 +253,10 @@ async def run_chess_game(process, console, username: str, opponent: str) -> None
             elif char == '\x7f' or char == '\b':  # Backspace
                 if move_buffer:
                     move_buffer = move_buffer[:-1]
-                    process.stdout.write('\b \b')
+                    process.stdout.write(b'\b \b')
             elif char.isprintable():
                 move_buffer += char
-                process.stdout.write(char)
+                process.stdout.write(char.encode('utf-8'))
                 
         except Exception as e:
             logger.error(f"Game input error: {e}")