diff --git a/tests/test_progitlib.py b/tests/test_progitlib.py
index e620a3f..b8108d9 100644
--- a/tests/test_progitlib.py
+++ b/tests/test_progitlib.py
@@ -243,6 +243,16 @@ class ProgitLibtests(tests.Modeltests):
         self.session.commit()
         self.assertEqual(msg, 'Tag added')
 
+        # Try a second time
+        msg = progit.lib.add_issue_tag(
+            session=self.session,
+            issue=issue,
+            tag='tag1',
+            user='pingou',
+            ticketfolder=None)
+        self.session.commit()
+        self.assertEqual(msg, 'Tag already present: tag1')
+
         issues = progit.lib.search_issues(self.session, repo, tags='tag1')
         self.assertEqual(len(issues), 1)
         self.assertEqual(issues[0].id, 1)