diff --git a/java/build.xml b/java/build.xml
index 76bcddb54..3bbe8a3e5 100644
--- a/java/build.xml
+++ b/java/build.xml
@@ -47,28 +47,29 @@
     <property name="uuc" value="@SuppressWarnings({ &quot;unused&quot;, &quot;unchecked&quot;, &quot;cast&quot; })${line.separator}" />
     <property name="uc" value="@SuppressWarnings({ &quot;unused&quot;, &quot;cast&quot; })${line.separator}" />
 
+    <!-- need to match against the previous line so that we don't re-add -->
     <replaceregexp 
         file="generated/processing/mode/java/preproc/JavaLexer.java"
-        match="(public class JavaLexer .*)" 
-        replace="${uuc}\1">
+        match="(\n\n)(public class JavaLexer .*)" 
+        replace="\1${uuc}\2">
     </replaceregexp>
 
     <replaceregexp 
         file="generated/processing/mode/java/preproc/JavaRecognizer.java"
-        match="(public class JavaRecognizer .*)" 
-        replace="${uc}\1">
+        match="(\*/\n)(public class JavaRecognizer .*)" 
+        replace="\1${uc}\2">
     </replaceregexp>
 
     <replaceregexp 
         file="generated/processing/mode/java/preproc/PdeLexer.java"
-        match="(public class PdeLexer .*)" 
-        replace="${uuc}\1">
+        match="(\n\n)(public class PdeLexer .*)" 
+        replace="\1${uuc}\2">
     </replaceregexp>
 
     <replaceregexp 
         file="generated/processing/mode/java/preproc/PdeRecognizer.java"
-        match="(public class PdeRecognizer .*)" 
-        replace="${uc}\1">
+        match="(\n\n)(public class PdeRecognizer .*)" 
+        replace="\1${uc}\2">
     </replaceregexp>
     <!-- end of workaround for old antlr -->
   </target>