Index: src/js/media/views/frame/edit-attachments.js
===================================================================
--- src/js/media/views/frame/edit-attachments.js	(revision 52725)
+++ src/js/media/views/frame/edit-attachments.js	(working copy)
@@ -251,7 +251,7 @@
 	 * focus is in a textarea or input field.
 	 */
 	keyEvent: function( event ) {
-		if ( ( 'INPUT' === event.target.nodeName || 'TEXTAREA' === event.target.nodeName ) && ! ( event.target.readOnly || event.target.disabled ) ) {
+		if ( ( 'INPUT' === event.target.nodeName || 'TEXTAREA' === event.target.nodeName ) && ! event.target.disabled ) {
 			return;
 		}