diff --git a/src/FormulaConverter.php b/src/FormulaConverter.php
index 3587a8d..45fbc53 100644
--- a/src/FormulaConverter.php
+++ b/src/FormulaConverter.php
@@ -134,7 +134,7 @@ private static function expandAtom($atom)
                                 $chunk = "({$what} == {$from} || {$what} == {$to})";
                                 break;
                             case '!=':
-                                $chunk = "({$what} != {$from}) && ({$what} == {$to})";
+                                $chunk = "{$what} != {$from} && {$what} != {$to}";
                                 break;
                         }
                     } else {