diff --git a/documentation/advanced.html b/documentation/advanced.html
index 51a7482fe..f7623435b 100644
--- a/documentation/advanced.html
+++ b/documentation/advanced.html
@@ -21,7 +21,7 @@ that will help you to get the most out of FLTK.</P>
     int main() {
       Fl::lock();
       /* run thread */
-      while (Fl::wait() &lt; 0) {
+      while (Fl::wait() &gt; 0) {
         if (Fl::thread_message()) {
           /* process your data */
         }