diff --git a/src/tests/junit/org/apache/tools/ant/BuildFileTest.java b/src/tests/junit/org/apache/tools/ant/BuildFileTest.java
index 2273826fc..3e84fd464 100644
--- a/src/tests/junit/org/apache/tools/ant/BuildFileTest.java
+++ b/src/tests/junit/org/apache/tools/ant/BuildFileTest.java
@@ -115,6 +115,14 @@ public abstract class BuildFileTest extends TestCase {
                    realLog.indexOf(substring) >= 0);
     }
 
+    /**
+     * Assert that the given substring is in the output messages.
+     * @since Ant1.7
+     */
+    public void assertOutputContaining(String substring) {
+        assertOutputContaining(null, substring);
+    }
+
     /**
      * Assert that the given substring is in the output messages.
      * @param message Print this message if the test fails. Defaults to 
@@ -139,7 +147,7 @@ public abstract class BuildFileTest extends TestCase {
         String realOutput = getOutput();
         String realMessage = (message != null) 
             ? message 
-            : "expecting output to contain \"" + substring + "\" output was \"" + realOutput + "\"";
+            : "expecting output to not contain \"" + substring + "\" output was \"" + realOutput + "\"";
         assertFalse(realMessage, realOutput.indexOf(substring) >= 0);
     }