diff --git a/lang/en/resource.php b/lang/en/resource.php
index ed093e8e80e..9250791a0e0 100644
--- a/lang/en/resource.php
+++ b/lang/en/resource.php
@@ -14,8 +14,8 @@ $string['filename'] = "File name";
 $string['fulltext'] = "Full text";
 $string['htmlfragment'] = "HTML fragment";
 $string['neverseen'] = "Never seen";
-$string['newheight'] = "Default window height";
-$string['newwidth'] = "Default window width";
+$string['newheight'] = "Default window height (in pixels)";
+$string['newwidth'] = "Default window width (in pixels)";
 $string['newfullscreen'] = "Fill the whole screen";
 $string['newresizable'] = "Allow the window to be resized";
 $string['newscrollbars'] = "Allow the window to be scrolled";