Index: _source/plugins/image/dialogs/image.js
===================================================================
--- _source/plugins/image/dialogs/image.js	(revision 6904)
+++ _source/plugins/image/dialogs/image.js	(revision )
@@ -158,12 +158,8 @@
 			else
 				ratioButton.addClass( 'cke_btn_unlocked' );
 
-			var lang = dialog._.editor.lang.image,
-				label =  lang[  dialog.lockRatio ? 'unlockRatio' : 'lockRatio' ];
+			ratioButton.setAttribute( 'aria-checked', dialog.lockRatio );
 
-			ratioButton.setAttribute( 'title', label );
-			ratioButton.getFirst().setText( label );
-
 			return dialog.lockRatio;
 		};
 
@@ -780,7 +776,7 @@
 																			updatePreview( this );
 																		}
 																	}
-																	evt.data.preventDefault();
+																	evt.data && evt.data.preventDefault();
 																}, this.getDialog() );
 															ratioButton.on( 'mouseover', function()
 																{
@@ -793,8 +789,8 @@
 														}
 													},
 													html : '<div>'+
-														'<a href="javascript:void(0)" tabindex="-1" title="' + editor.lang.image.unlockRatio +
-														'" class="cke_btn_locked" id="' + btnLockSizesId + '" role="button"><span class="cke_label">' + editor.lang.image.unlockRatio + '</span></a>' +
+														'<a href="javascript:void(0)" tabindex="-1" title="' + editor.lang.image.lockRatio +
+														'" class="cke_btn_locked" id="' + btnLockSizesId + '" role="checkbox"><span class="cke_label">' + editor.lang.image.lockRatio + '</span></a>' +
 														'<a href="javascript:void(0)" tabindex="-1" title="' + editor.lang.image.resetSize +
 														'" class="cke_btn_reset" id="' + btnResetSizeId + '" role="button"><span class="cke_label">' + editor.lang.image.resetSize + '</span></a>'+
 														'</div>'
Index: _source/lang/en.js
===================================================================
--- _source/lang/en.js	(revision 6904)
+++ _source/lang/en.js	(revision )
@@ -413,7 +413,6 @@
 		upload		: 'Upload',
 		alt			: 'Alternative Text',
 		lockRatio	: 'Lock Ratio',
-		unlockRatio	: 'Unlock Ratio',
 		resetSize	: 'Reset Size',
 		border		: 'Border',
 		hSpace		: 'HSpace',