diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 8ec6458..1680844 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
 - repo: https://github.com/ambv/black
-  rev: 21.7b0
+  rev: 22.3.0
   hooks:
   - id: black
 - repo: https://github.com/PyCQA/flake8
diff --git a/arris_tg2492lg/connect_box.py b/arris_tg2492lg/connect_box.py
index 7cf718b..5e40a23 100644
--- a/arris_tg2492lg/connect_box.py
+++ b/arris_tg2492lg/connect_box.py
@@ -9,6 +9,7 @@
 from dataclasses import dataclass
 from datetime import datetime
 from typing import Any, List, Optional
+from urllib.parse import quote
 from yarl import URL
 
 from .const import (
@@ -35,11 +36,10 @@ def __init__(self, websession: ClientSession, hostname: str, password: str):
         self._credential: Optional[Credential] = None
 
     async def async_login(self) -> str:
-        arg_string = f"{USERNAME}:{self._password}"
+        arg_string = f"{quote(USERNAME)}:{quote(self._password)}"
         arg = base64.b64encode(arg_string.encode("utf-8")).decode("ascii")
 
-        params = {"arg": arg, "_n": self._nonce}
-        async with self._websession.get(f"{self._hostname}/login", params=params) as response:
+        async with self._websession.get(f"{self._hostname}/login?arg={arg}&_n={self._nonce}") as response:
             response.raise_for_status()
 
             token = await response.text()
diff --git a/tests/test_connect_box.py b/tests/test_connect_box.py
index 80153c7..e57b720 100644
--- a/tests/test_connect_box.py
+++ b/tests/test_connect_box.py
@@ -59,6 +59,51 @@ async def get_html_response(request):
         await connect_box.async_login()
 
 
+async def test_login_url_replaces_special_characters_in_password(aiohttp_client):
+    """Validates that special characters in the password are replaced.
+    The webpage of the router replaces special characters in both the username and password using the '%xx' escape.
+    """
+
+    async def login_result(request):
+        login_result.url = str(request.url)
+        return await _get_credential(request)
+
+    login_result.url = ""
+
+    app = web.Application()
+    app.router.add_get("/login", login_result)
+    client = await aiohttp_client(app)
+
+    connect_box = ConnectBox(client.session, f"http://{client.host}:{client.port}", "&=")
+
+    token = await connect_box.async_login()
+
+    assert token == "eyJuYW1lIjogImFkbWluIn0="  # base64 representation of: {"name": "admin"}
+    assert login_result.url.startswith(f"http://{client.host}:{client.port}/login?arg=YWRtaW46JTI2JTNE&_n=")
+
+
+async def test_login_does_not_url_encode_base64(aiohttp_client):
+    """Validate that the characters in the base64 arg parameter are not replaced.
+    The portal of the router does not replace special characters (=) in the base64 encoded parameter.
+    """
+
+    async def login_result(request):
+        login_result.url = str(request.url)
+        return await _get_credential(request)
+
+    login_result.url = ""
+
+    app = web.Application()
+    app.router.add_get("/login", login_result)
+    client = await aiohttp_client(app)
+
+    connect_box = ConnectBox(client.session, f"http://{client.host}:{client.port}", "secret2")
+
+    await connect_box.async_login()
+
+    assert login_result.url.startswith(f"http://{client.host}:{client.port}/login?arg=YWRtaW46c2VjcmV0Mg==&_n=")
+
+
 async def test_get_connected_devices(aiohttp_client):
     app = web.Application()
     app.router.add_get("/login", _get_credential)