diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 9c411ea7caf..662a49eb86c 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -10577,9 +10577,11 @@ function dol_eval($s, $returnvalue = 1, $hideerrors = 1, $onlysimplestring = '1'
 				$scheck = preg_replace('/\s\(/', '__PARENTHESIS__ ', $scheck);	// accept parenthesis in '... (' like in 'if ($a == 1)'. Must replace with __PARENTHESIS__ with a space after to allow following substitutions
 				$scheck = preg_replace('/^!?[a-zA-Z0-9_]+\(/', '__FUNCTION__', $scheck); // accept parenthesis in 'function(' and '!function('
 				$scheck = preg_replace('/\s!?[a-zA-Z0-9_]+\(/', '__FUNCTION__', $scheck); // accept parenthesis in '... function(' and '... !function('
+				$scheck = preg_replace('/^!\(/', '__NOTANDPARENTHESIS__', $scheck); // accept parenthesis in '!('
+				$scheck = preg_replace('/\s!\(/', '__NOTANDPARENTHESIS__', $scheck); // accept parenthesis in '... !('
 				$scheck = preg_replace('/(\^|\')\(/', '__REGEXSTART__', $scheck);	// To allow preg_match('/^(aaa|bbb)/'...  or  isStringVarMatching('leftmenu', '(aaa|bbb)')
 			}
-			//print 'scheck='.$scheck." : ".strpos($scheck, '(')."<br>\n";
+
 			if (strpos($scheck, '(') !== false) {
 				if ($returnvalue) {
 					return 'Bad string syntax to evaluate (mode '.$onlysimplestring.', found call of a function or method without using the direct name of the function): '.$s;