diff --git a/java/src/com/tightvnc/rfbplayer/VncCanvas.java b/java/src/com/tightvnc/rfbplayer/VncCanvas.java
index b369c63..9ebf695 100644
--- a/java/src/com/tightvnc/rfbplayer/VncCanvas.java
+++ b/java/src/com/tightvnc/rfbplayer/VncCanvas.java
@@ -105,7 +105,7 @@
     paint(g);
   }
 
-  public void paint(Graphics g) {
+  public synchronized void paint(Graphics g) {
     synchronized(memImage) {
       g.drawImage(memImage, 0, 0, null);
     }