diff --git a/CHANGELOG.md b/CHANGELOG.md
index 92522cd..533553d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -55,6 +55,7 @@
 
 - [#111](https://github.com/pusher/oauth2_proxy/pull/111) Add option for telling where to find a login.gov JWT key file (@timothy-spencer)
 - [#170](https://github.com/pusher/oauth2_proxy/pull/170) Restore binary tarball contents to be compatible with bitlys original tarballs (@zeha)
+- [#185](https://github.com/pusher/oauth2_proxy/pull/185) Fix an unsupported protocol scheme error during token validation when using the Azure provider (@jonas)
 
 # v3.2.0
 
diff --git a/providers/internal_util.go b/providers/internal_util.go
index 7144dee..849e2c7 100644
--- a/providers/internal_util.go
+++ b/providers/internal_util.go
@@ -47,7 +47,7 @@ func stripParam(param, endpoint string) string {
 
 // validateToken returns true if token is valid
 func validateToken(p Provider, accessToken string, header http.Header) bool {
-	if accessToken == "" || p.Data().ValidateURL == nil {
+	if accessToken == "" || p.Data().ValidateURL == nil || p.Data().ValidateURL.String() == "" {
 		return false
 	}
 	endpoint := p.Data().ValidateURL.String()