diff --git a/src/tests/junit/org/apache/tools/ant/taskdefs/ConcatTest.java b/src/tests/junit/org/apache/tools/ant/taskdefs/ConcatTest.java
index f26f8c5bc..b5f91737a 100644
--- a/src/tests/junit/org/apache/tools/ant/taskdefs/ConcatTest.java
+++ b/src/tests/junit/org/apache/tools/ant/taskdefs/ConcatTest.java
@@ -274,7 +274,8 @@ public class ConcatTest
         executeTarget("testTranscoding");
         File f1 = getProject().resolveFile("copy/expected/utf-8");
         File f2 = getProject().resolveFile("concat.utf8");
-        assertTrue(FILE_UTILS.contentEquals(f1, f2));
+        assertTrue(f1.toString() + " differs from " + f2.toString(),
+                FILE_UTILS.contentEquals(f1, f2));
     }
 
     public void testResources() {