diff --git a/src/wp-admin/js/customize-controls.js b/src/wp-admin/js/customize-controls.js
index f8a64dc2dd..3c201bf6c0 100644
--- a/src/wp-admin/js/customize-controls.js
+++ b/src/wp-admin/js/customize-controls.js
@@ -723,6 +723,7 @@
 					}
 				} );
 				topPanel.attr( 'tabindex', '-1' );
+				changeBtn.attr( 'tabindex', '-1' );
 				customizeBtn.focus();
 			} else {
 				siblings.removeClass( 'open' );
@@ -735,6 +736,7 @@
 					}
 				} );
 				topPanel.attr( 'tabindex', '0' );
+				customizeBtn.attr( 'tabindex', '0' );
 				changeBtn.focus();
 				container.scrollTop( 0 );
 			}