diff --git a/dynatrace/environment_v2/extensions.py b/dynatrace/environment_v2/extensions.py
index 6d127f1..0820e33 100644
--- a/dynatrace/environment_v2/extensions.py
+++ b/dynatrace/environment_v2/extensions.py
@@ -100,7 +100,8 @@ def post(self, zip_file_path: Union[str, Path], validate_only: Optional[bool] =
         file = Path(zip_file_path)
         with open(file, "rb") as f:
             response = self.__http_client.make_request(f"{self.ENDPOINT}",
-                                                       params=params,
+                                                       query_params=params,
+                                                       headers={"Content-Type": "application/octet-stream"},
                                                        method="POST",
                                                        files={"file": f}).json()
             return Extension(raw_element=response)
diff --git a/setup.py b/setup.py
index fe63518..0d31fed 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@
 
 setup(
     name="dt",
-    version="1.1.66",
+    version="1.1.67",
     packages=find_packages(),
     install_requires=["requests>=2.22"],
     tests_require=["pytest", "mock", "tox"],