diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2416a0a..b570f6e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Fixed
+- Change HTTP method strings to uppercase @fitudao3788
 
 ### Added
 
diff --git a/zendriver/core/browser.py b/zendriver/core/browser.py
index f22bbca..368d6b7 100644
--- a/zendriver/core/browser.py
+++ b/zendriver/core/browser.py
@@ -839,10 +839,10 @@ async def get(self, endpoint: str) -> Any:
         return await self._request(endpoint)
 
     async def post(self, endpoint: str, data: dict[str, str]) -> Any:
-        return await self._request(endpoint, method="post", data=data)
+        return await self._request(endpoint, method="POST", data=data)
 
     async def _request(
-        self, endpoint: str, method: str = "get", data: dict[str, str] | None = None
+        self, endpoint: str, method: str = "GET", data: dict[str, str] | None = None
     ) -> Any:
         url = urllib.parse.urljoin(
             self.api, f"json/{endpoint}" if endpoint else "/json"