diff --git a/javascript/MemberTableField.js b/javascript/MemberTableField.js
index f376a882..f9ca0b49 100755
--- a/javascript/MemberTableField.js
+++ b/javascript/MemberTableField.js
@@ -279,3 +279,38 @@ MemberFilterButton.prototype = {
 Behaviour.register({
 	'#Form_EditForm div.MemberTableField table.data input.text' : AjaxMemberLookup
 });
+
+(function($) {
+	Behaviour.register({
+		/**
+		 * Automatically check and disable all checkboxes if ADMIN permissions are selected.
+		 * As they're disabled, any changes won't be submitted (which is intended behaviour),
+		 * checking all boxes is purely presentational.
+		 */
+		'#Permissions .valADMIN input': {
+			initialize: function() {
+				this.toggleCheckboxes();
+			},
+			onclick: function(e) {
+				this.toggleCheckboxes();
+			},
+			toggleCheckboxes: function() {
+				var checkboxes = $(this).parents('.field:eq(0)').find('.checkbox').not(this);
+
+				if($(this).is(':checked')) {
+					checkboxes.each(function() {
+						$(this).data('SecurityAdmin.oldChecked', $(this).attr('checked'));
+						$(this).data('SecurityAdmin.oldDisabled', $(this).attr('disabled'));
+						$(this).attr('disabled', 'disabled');
+						$(this).attr('checked', 'checked');
+					});
+				} else {
+					checkboxes.each(function() {
+						$(this).attr('checked', $(this).data('SecurityAdmin.oldChecked'));
+						$(this).attr('disabled', $(this).data('SecurityAdmin.oldDisabled'));
+					});
+				}
+			}
+		}
+	});
+}(jQuery));
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