diff --git a/tests/agent/test_redact.py b/tests/agent/test_redact.py
index 75fd3b6f73b..ed7e4255887 100644
--- a/tests/agent/test_redact.py
+++ b/tests/agent/test_redact.py
@@ -41,6 +41,12 @@ class TestKnownPrefixes:
         result = redact_sensitive_text(token)
         assert "a" * 14 not in result
 
+    def test_slack_app_token(self):
+        token = "xapp-1-A1234567890-B1234567890-C1234567890"
+        result = redact_sensitive_text(token)
+        assert "A1234567890-B1234567890-C1234567890" not in result
+        assert "xapp-1" in result
+
     def test_google_api_key(self):
         result = redact_sensitive_text("AIzaSyB-abc123def456ghi789jklmno012345")
         assert "abc123def456" not in result