diff --git a/core/pkg/ingress/annotations/authreq/main.go b/core/pkg/ingress/annotations/authreq/main.go
index 016cc2624..8b156766e 100644
--- a/core/pkg/ingress/annotations/authreq/main.go
+++ b/core/pkg/ingress/annotations/authreq/main.go
@@ -131,22 +131,10 @@ func (a authReq) Parse(ing *extensions.Ingress) (interface{}, error) {
 
 	return &External{
 		URL:             str,
-		Host:            stripPort(ur.Host),
+		Host:            ur.Hostname(),
 		SigninURL:       signin,
 		Method:          m,
 		SendBody:        sb,
 		ResponseHeaders: h,
 	}, nil
 }
-
-// TODO: Remove after upgrade to Go 1.8
-func stripPort(hostport string) string {
-	colon := strings.IndexByte(hostport, ':')
-	if colon == -1 {
-		return hostport
-	}
-	if i := strings.IndexByte(hostport, ']'); i != -1 {
-		return strings.TrimPrefix(hostport[:i], "[")
-	}
-	return hostport[:colon]
-}