diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 9311adb11ef..bb69fd4966d 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -9768,7 +9768,7 @@ function natural_search($fields, $value, $mode = 0, $nofirstand = 0)
 		$value = preg_replace('/\*/', '%', $value); // Replace * with %
 	}
 	if ($mode == 1) {
-		$value = preg_replace('/([<>=]+)\s+([0-9'.preg_quote($langs->trans("DecimalSeparator"), '/').'\-])/', '\1\2', $value); // Clean string '< 10' into '<10' so we can the explode on space to get all tests to do
+		$value = preg_replace('/([!<>=]+)\s+([0-9'.preg_quote($langs->trans("DecimalSeparator"), '/').'\-])/', '\1\2', $value); // Clean string '< 10' into '<10' so we can the explode on space to get all tests to do
 	}
 
 	$value = preg_replace('/\s*\|\s*/', '|', $value);
@@ -9788,10 +9788,10 @@ function natural_search($fields, $value, $mode = 0, $nofirstand = 0)
 		foreach ($fields as $field) {
 			if ($mode == 1) {
 				$operator = '=';
-				$newcrit = preg_replace('/([<>=]+)/', '', $crit);
+				$newcrit = preg_replace('/([!<>=]+)/', '', $crit);
 
 				$reg = array();
-				preg_match('/([<>=]+)/', $crit, $reg);
+				preg_match('/([!<>=]+)/', $crit, $reg);
 				if (!empty($reg[1])) {
 					$operator = $reg[1];
 				}