diff --git a/src/wp-admin/css/common.css b/src/wp-admin/css/common.css
index c5c4e70566..e4b01914e1 100644
--- a/src/wp-admin/css/common.css
+++ b/src/wp-admin/css/common.css
@@ -2003,6 +2003,8 @@ div.action-links {
 
 /* Thickbox for Plugin Install screen */
 body.plugin-install-php #TB_window,
+body.plugins-php #TB_window,
+body.update-core-php #TB_window,
 body.index-php #TB_window {
 	background: #fcfcfc url( ../images/spinner.gif ) no-repeat center;
 }
@@ -2011,8 +2013,10 @@ body.index-php #TB_window {
 	(-o-min-device-pixel-ratio: 5/4),
 	(-webkit-min-device-pixel-ratio: 1.25),
 	(min-resolution: 120dpi) {
-	
+
 	body.plugin-install-php #TB_window,
+	body.plugins-php #TB_window,
+	body.update-core-php #TB_window,
 	body.index-php #TB_window {
 		background: #fcfcfc url( ../images/spinner-2x.gif ) no-repeat center;
 		-webkit-background-size: 20px 20px;
@@ -2021,17 +2025,23 @@ body.index-php #TB_window {
 }
 
 body.plugin-install-php #TB_title,
+body.plugins-php #TB_title,
+body.update-core-php #TB_title,
 body.index-php #TB_title {
 	float: left;
 	height: 1px;
 }
 
 body.plugin-install-php #TB_ajaxWindowTitle,
+body.plugins-php #TB_ajaxWindowTitle,
+body.update-core-php #TB_ajaxWindowTitle,
 body.index-php #TB_ajaxWindowTitle {
 	display: none;
 }
 
 body.plugin-install-php .tb-close-icon,
+body.plugins-php .tb-close-icon,
+body.update-core-php .tb-close-icon,
 body.index-php .tb-close-icon {
 	line-height: 48px;
 	width: 48px;
@@ -2039,6 +2049,8 @@ body.index-php .tb-close-icon {
 }
 
 body.plugin-install-php .tb-close-icon:before,
+body.plugins-php .tb-close-icon:before,
+body.update-core-php .tb-close-icon:before,
 body.index-php .tb-close-icon:before {
 	line-height: 48px;
 }