fix error message
diff --git a/src/main/org/apache/ant/compress/taskdefs/ExpandBase.java b/src/main/org/apache/ant/compress/taskdefs/ExpandBase.java
index d75de09..cb57760 100644
--- a/src/main/org/apache/ant/compress/taskdefs/ExpandBase.java
+++ b/src/main/org/apache/ant/compress/taskdefs/ExpandBase.java
@@ -75,7 +75,7 @@
      */
     public void setScanForUnicodeExtraFields(boolean b) {
         throw new BuildException("The " + getTaskName()
-                                 + " task doesn't support the encoding"
+                                 + " task doesn't support the scanForUnicodeExtraFields"
                                  + " attribute", getLocation());
     }