Index: src/wp-admin/themes.php
===================================================================
--- src/wp-admin/themes.php	(revision 31832)
+++ src/wp-admin/themes.php	(working copy)
@@ -177,9 +177,9 @@
 
 				if ( current_user_can( 'customize' ) ) {
 					if ( 'custom-header' === $menu_file ) {
-						$current_theme_actions[] = "<a class='button button-secondary hide-if-no-customize$class' href='customize.php?autofocus[control]=header_image'>{$item[0]}</a>";
+						$current_theme_actions[] = "<a class='button button-secondary hide-if-no-customize$class' href='" . admin_url( add_query_arg( array( 'autofocus[control]' => 'header_image' ), 'customize.php' ) ) . "'>{$item[0]}</a>";
 					} elseif ( 'custom-background' === $menu_file ) {
-						$current_theme_actions[] = "<a class='button button-secondary hide-if-no-customize$class' href='customize.php?autofocus[control]=background_image'>{$item[0]}</a>";
+						$current_theme_actions[] = "<a class='button button-secondary hide-if-no-customize$class' href='" . admin_url( add_query_arg( array( 'autofocus[control]' => 'background_image' ), 'customize.php' ) ) .  "'>{$item[0]}</a>";
 					}
 				}
 
@@ -188,9 +188,9 @@
 				}
 
 				if ( file_exists( ABSPATH . "wp-admin/$menu_file" ) ) {
-					$current_theme_actions[] = "<a class='button button-secondary$class' href='{$item[2]}'>{$item[0]}</a>";
+					$current_theme_actions[] = "<a class='button button-secondary$class' href='" . admin_url( $item[2] ) . "'>{$item[0]}</a>";
 				} else {
-					$current_theme_actions[] = "<a class='button button-secondary$class' href='themes.php?page={$item[2]}'>{$item[0]}</a>";
+					$current_theme_actions[] = "<a class='button button-secondary$class' href='" . admin_url( add_query_arg( array( 'page' => $item[2] ), 'themes.php' ) ) . "'>{$item[0]}</a>";
 				}
 			}
 		}