diff --git a/src/wp-admin/js/media-upload.js b/src/wp-admin/js/media-upload.js
index 0261b9b751..7e6eed23da 100644
--- a/src/wp-admin/js/media-upload.js
+++ b/src/wp-admin/js/media-upload.js
@@ -43,8 +43,8 @@ var tb_position;
 			W = ( 720 < width ) ? 720 : width,
 			adminbar_height = 0;
 
-		if ( $('body.admin-bar').length ) {
-			adminbar_height = parseInt( jQuery('#wpadminbar').css('height'), 10 );
+		if ( $('#wpadminbar').length ) {
+			adminbar_height = parseInt( $('#wpadminbar').css('height'), 10 );
 		}
 
 		if ( tbWindow.size() ) {
diff --git a/src/wp-admin/js/plugin-install.js b/src/wp-admin/js/plugin-install.js
index a5029ece39..f204757bf7 100644
--- a/src/wp-admin/js/plugin-install.js
+++ b/src/wp-admin/js/plugin-install.js
@@ -10,8 +10,8 @@ jQuery(document).ready(function($) {
 			W = ( 720 < width ) ? 720 : width,
 			adminbar_height = 0;
 
-		if ( $('body.admin-bar').length ) {
-			adminbar_height = parseInt( jQuery('#wpadminbar').css('height'), 10 );
+		if ( $('#wpadminbar').length ) {
+			adminbar_height = parseInt( $('#wpadminbar').css('height'), 10 );
 		}
 
 		if ( tbWindow.size() ) {
diff --git a/src/wp-admin/js/theme.js b/src/wp-admin/js/theme.js
index aba7d9b946..6647a0d79a 100644
--- a/src/wp-admin/js/theme.js
+++ b/src/wp-admin/js/theme.js
@@ -769,8 +769,8 @@ jQuery(document).ready( function($) {
 			W = ( 1040 < width ) ? 1040 : width,
 			adminbar_height = 0;
 
-		if ( $('body.admin-bar').length ) {
-			adminbar_height = parseInt( jQuery('#wpadminbar').css('height'), 10 );
+		if ( $('#wpadminbar').length ) {
+			adminbar_height = parseInt( $('#wpadminbar').css('height'), 10 );
 		}
 
 		if ( tbWindow.size() ) {