diff --git a/phpBB/adm/style/overall_header.html b/phpBB/adm/style/overall_header.html
index 1e8de766ff..8279ac34dc 100644
--- a/phpBB/adm/style/overall_header.html
+++ b/phpBB/adm/style/overall_header.html
@@ -54,7 +54,7 @@ function marklist(id, name, state)
 
 	for (var r = 0; r < rb.length; r++)
 	{
-		if (rb[r].name.substr(0, name.length) == name)
+		if (rb[r].name.substr(0, name.length) == name && rb[r].disabled !== true)
 		{
 			rb[r].checked = state;
 		}
diff --git a/phpBB/adm/style/simple_header.html b/phpBB/adm/style/simple_header.html
index 9f47b2052b..439645a211 100644
--- a/phpBB/adm/style/simple_header.html
+++ b/phpBB/adm/style/simple_header.html
@@ -66,7 +66,7 @@ function marklist(id, name, state)
 	
 	for (var r = 0; r < rb.length; r++)
 	{
-		if (rb[r].name.substr(0, name.length) == name)
+		if (rb[r].name.substr(0, name.length) == name && rb[r].disabled !== true)
 		{
 			rb[r].checked = state;
 		}
diff --git a/phpBB/styles/prosilver/template/forum_fn.js b/phpBB/styles/prosilver/template/forum_fn.js
index b803a6f5c8..f1d423d269 100644
--- a/phpBB/styles/prosilver/template/forum_fn.js
+++ b/phpBB/styles/prosilver/template/forum_fn.js
@@ -57,7 +57,7 @@ function marklist(id, name, state) {
 
 	jQuery('#' + id + ' input[type=checkbox][name]').each(function() {
 		var $this = jQuery(this);
-		if ($this.attr('name').substr(0, name.length) === name) {
+		if ($this.attr('name').substr(0, name.length) === name && !$this.prop('disabled')) {
 			$this.prop('checked', state);
 		}
 	});