diff --git a/indra/newview/app_settings/cmd_line.xml b/indra/newview/app_settings/cmd_line.xml
index 294d85eac13545d9574b3592dc2d91e8911a54b5..e4ac455e7cb659ecb95274e2390e271ebb9315bf 100644
--- a/indra/newview/app_settings/cmd_line.xml
+++ b/indra/newview/app_settings/cmd_line.xml
@@ -392,13 +392,6 @@
       <string>CrashOnStartup</string>
     </map>
 
-    <key>fullscreen</key>
-    <map>
-      <key>desc</key>
-      <string>Force full screen mode</string>
-      <key>map-to</key>
-      <string>WindowFullScreen</string>
-    </map>
     <key>disablecrashlogger</key>
     <map>
       <key>desc</key>
diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index cd53fb89704daa3211f356a4cf5c142aa405f785..b460885a53134d533e1bc6589a1ea3bddda8f346 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -505,6 +505,9 @@ static void settings_modify()
 	gSavedSettings.setBOOL("VectorizeEnable", FALSE );
 	gSavedSettings.setU32("VectorizeProcessor", 0 );
 	gSavedSettings.setBOOL("VectorizeSkin", FALSE);
+
+	// disable fullscreen mode, unsupported
+	gSavedSettings.setBOOL("WindowFullScreen", FALSE);
 #endif
 }