diff --git a/etemplate/inc/class.uietemplate.inc.php b/etemplate/inc/class.uietemplate.inc.php
index 20c2a81033..053965cd3b 100644
--- a/etemplate/inc/class.uietemplate.inc.php
+++ b/etemplate/inc/class.uietemplate.inc.php
@@ -1004,9 +1004,9 @@ class etemplate extends boetemplate
 				$cell['onchange'] = $this->expand_name($cell['onchange'],$show_c,$show_row,$content['.c'],$content['.row'],$content);
 			}
 			if (!$ext_type) $ext_type = $type;
-			$extension_readonly = $readonlys[$name] || $readonlys['__ALL__'];
-			$extra_label = $this->extensionPreProcess($type,$form_name,$value,$cell,$extension_readonly);
-			$readonlys[$name] =& $extension_readonly;
+			// if readonlys[__ALL__] is set, also set readonlys[$name] (but only then as for extensions (eg. tabs) $readonlys[$name] can be an array!)
+			if ($readonlys['__ALL__']) $readonlys[$name] = true;
+			$extra_label = $this->extensionPreProcess($type,$form_name,$value,$cell,$readonlys[$name]);
 
 			$readonly = $cell['readonly'] !== false && ($readonly || $cell['readonly']);	// might be set or unset (===false) by extension