diff --git a/WHATSNEW b/WHATSNEW
index f720b6439..0213e6a4c 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -136,6 +136,9 @@ Fixed bugs:
 
 * perform proper uptodate check in <rmic> when compiling for IIOP.
 
+* <jjtree>'s uptodate test works even if outputdirectory is not the
+  parent dir of target
+
 Changes from Ant 1.2 to Ant 1.3
 ===========================================
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/javacc/JJTree.java b/src/main/org/apache/tools/ant/taskdefs/optional/javacc/JJTree.java
index 53d8145f0..fda6421ac 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/javacc/JJTree.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/javacc/JJTree.java
@@ -187,8 +187,9 @@ public class JJTree extends Task {
         cmdl.createArgument().setValue(
             "-OUTPUT_DIRECTORY:"+outputDirectory.getAbsolutePath().replace('\\', '/'));
         
-        final File javaFile = new File(
-            target.toString().substring(0, target.toString().indexOf(".jjt")) + ".jj");
+        String targetName = target.getName();
+        final File javaFile = new File(outputDirectory,
+            targetName.substring(0, targetName.indexOf(".jjt")) + ".jj");
         if (javaFile.exists() && target.lastModified() < javaFile.lastModified()) {
             project.log("Target is already built - skipping (" + target + ")");
             return;