diff --git a/src/prettify/gui/JTextComponentRowHeader.java b/src/prettify/gui/JTextComponentRowHeader.java
index 0e660f4..711febe 100644
--- a/src/prettify/gui/JTextComponentRowHeader.java
+++ b/src/prettify/gui/JTextComponentRowHeader.java
@@ -502,11 +502,7 @@
    * @return a copy of the list
    */
   public List<Integer> getHighlightedLineList() {
-    List<Integer> returnList;
-    synchronized (highlightedLineList) {
-      returnList = new ArrayList<Integer>(highlightedLineList);
-    }
-    return returnList;
+    return new ArrayList<Integer>(highlightedLineList);
   }
 
   /**
diff --git a/src/prettify/gui/SyntaxHighlighterPane.java b/src/prettify/gui/SyntaxHighlighterPane.java
index 278d282..d3c0dd0 100644
--- a/src/prettify/gui/SyntaxHighlighterPane.java
+++ b/src/prettify/gui/SyntaxHighlighterPane.java
@@ -446,11 +446,7 @@
    * @return a copy of the list
    */
   public List<Integer> getHighlightedLineList() {
-    List<Integer> returnList;
-    synchronized (highlightedLineList) {
-      returnList = new ArrayList<Integer>(highlightedLineList);
-    }
-    return returnList;
+    return new ArrayList<Integer>(highlightedLineList);
   }
 
   /**