diff --git a/vncviewer/DesktopWindow.cxx b/vncviewer/DesktopWindow.cxx
index 9101951..102e0b1 100644
--- a/vncviewer/DesktopWindow.cxx
+++ b/vncviewer/DesktopWindow.cxx
@@ -173,6 +173,9 @@
   repositionViewport();
 
   // Update allowed resize range
+#ifdef HAVE_FLTK_FULLSCREEN
+  if (!fullscreen_active())
+#endif
   size_range(100, 100, new_w, new_h);
 
   // repositionViewport() makes sure the scroll widget notices any changes