diff --git a/azure/azure.go b/azure/azure.go
deleted file mode 100644
index 171b264..0000000
--- a/azure/azure.go
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2017 The oauth2 Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package azure provides constants for using OAuth2 to access Azure Active Directory (Azure AD).
-package azure
-
-import (
-	"golang.org/x/oauth2"
-)
-
-// Endpoint is the Azure Active Directory (Azure AD) OAuth 2.0 endpoint.
-var Endpoint = oauth2.Endpoint{
-	AuthURL:  "https://login.microsoftonline.com/common/oauth2/v2.0/authorize",
-	TokenURL: "https://login.microsoftonline.com/common/oauth2/v2.0/token",
-}
diff --git a/microsoft/microsoft.go b/microsoft/microsoft.go
index 2fe8afc..3ffbc57 100644
--- a/microsoft/microsoft.go
+++ b/microsoft/microsoft.go
@@ -15,11 +15,15 @@ var LiveConnectEndpoint = oauth2.Endpoint{
 	TokenURL: "https://login.live.com/oauth20_token.srf",
 }
 
-// AzureActiveDirectoryEndpoint returns a new oauth2.Endpoint for the given tenant at Azure Active Directory.
+// AzureADEndpoint returns a new oauth2.Endpoint for the given tenant at Azure Active Directory.
+// If tenant is empty, it uses the tenant called `common`.
 //
 // For more information see:
 // https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-v2-protocols#endpoints
-func AzureActiveDirectoryEndpoint(tenant string) oauth2.Endpoint {
+func AzureADEndpoint(tenant string) oauth2.Endpoint {
+	if tenant == "" {
+		tenant = "common"
+	}
 	return oauth2.Endpoint{
 		AuthURL:  "https://login.microsoftonline.com/" + tenant + "/oauth2/v2.0/authorize",
 		TokenURL: "https://login.microsoftonline.com/" + tenant + "/oauth2/v2.0/token",