diff --git a/google/cloud/storage/_http.py b/google/cloud/storage/_http.py
index 0ade1525f..8eaee23c0 100644
--- a/google/cloud/storage/_http.py
+++ b/google/cloud/storage/_http.py
@@ -39,7 +39,15 @@ class Connection(_http.JSONConnection):
 
     def __init__(self, client, client_info=None, api_endpoint=None):
         super(Connection, self).__init__(client, client_info)
-        self.API_BASE_URL = api_endpoint or self.DEFAULT_API_ENDPOINT
+        self.API_BASE_URL = (
+            api_endpoint or self.DEFAULT_API_ENDPOINT + "/storage/{self.API_VERSION}"
+        )
+        # A template for the URL of a particular API call.
+        self.API_URL_TEMPLATE = (
+            "{api_base_url}/storage/{api_version}{path}"
+            if api_endpoint is None
+            else "{api_base_url}{path}"
+        )
         self.API_BASE_MTLS_URL = self.DEFAULT_API_MTLS_ENDPOINT
         self.ALLOW_AUTO_SWITCH_TO_MTLS_URL = api_endpoint is None
         self._client_info.client_library_version = __version__
@@ -54,9 +62,6 @@ def __init__(self, client, client_info=None, api_endpoint=None):
     API_VERSION = "v1"
     """The version of the API, used in building the API call's URL."""
 
-    API_URL_TEMPLATE = "{api_base_url}/storage/{api_version}{path}"
-    """A template for the URL of a particular API call."""
-
     def api_request(self, *args, **kwargs):
         retry = kwargs.pop("retry", None)
         call = functools.partial(super(Connection, self).api_request, *args, **kwargs)