diff --git a/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFFormulaEvaluation.java b/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFFormulaEvaluation.java
index 84a4aa6800..3b1fdd3cad 100644
--- a/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFFormulaEvaluation.java
+++ b/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFFormulaEvaluation.java
@@ -256,6 +256,7 @@ public final class TestXSSFFormulaEvaluation extends BaseTestFormulaEvaluator {
     @Ignore
     public void testCachedReferencesToOtherWorkbooks() throws Exception {
         // TODO
+        fail("unit test not written yet");
     }
     
     /**