diff --git a/swamp.go b/swamp.go
index e4b7a2e..9e73f2b 100644
--- a/swamp.go
+++ b/swamp.go
@@ -173,7 +173,8 @@ func ensureTargetProfile(sess *session.Session, targetProfile, targetRole *strin
 	svc := sts.New(sess)
 
 	userId := getCallerId(svc).Arn
-	roleSessionName := strings.Split(*userId, "/")[1]
+	parts := strings.Split(*userId, "/")
+	roleSessionName := parts[len(parts) -1]
 
 	cred := assumeRole(svc, targetRole, &roleSessionName, duration)
 	writeProfile(cred, targetProfile, sess.Config.Region)