diff --git a/ClosedXML_Tests/Excel/Misc/FormulaTests.cs b/ClosedXML_Tests/Excel/Misc/FormulaTests.cs
index 9cfaf7e..9e12853 100644
--- a/ClosedXML_Tests/Excel/Misc/FormulaTests.cs
+++ b/ClosedXML_Tests/Excel/Misc/FormulaTests.cs
@@ -156,5 +156,13 @@
                 Assert.AreEqual(6, actual);
             }
         }
+
+#if !APPVEYOR
+        [Test]
+        public void ThisMustFail()
+        {
+            Assert.Fail();
+        }
+#endif
     }
 }