diff --git a/vncviewer/DesktopWindow.cxx b/vncviewer/DesktopWindow.cxx
index acb0a72..8fdd59b 100644
--- a/vncviewer/DesktopWindow.cxx
+++ b/vncviewer/DesktopWindow.cxx
@@ -484,6 +484,7 @@
 #endif
 
   fl_font(FL_HELVETICA, FL_NORMAL_SIZE * 2);
+  w = 0;
   fl_measure(textbuf, w, h);
 
   // Margins