diff --git a/vncviewer/Viewport.cxx b/vncviewer/Viewport.cxx
index 08ca272..0936a63 100644
--- a/vncviewer/Viewport.cxx
+++ b/vncviewer/Viewport.cxx
@@ -884,8 +884,11 @@
   case ID_FULLSCREEN:
     if (window()->fullscreen_active())
       window()->fullscreen_off();
-    else
+    else {
+      // See comment in DesktopWindow::handleOptions
+      window()->size_range(100, 100, 0, 0);
       window()->fullscreen();
+    }
     break;
 #endif
   case ID_CTRL: