diff --git a/src/SequenceMatcher.php b/src/SequenceMatcher.php
index 6c9e26c..df5640f 100644
--- a/src/SequenceMatcher.php
+++ b/src/SequenceMatcher.php
@@ -404,7 +404,7 @@ public function getOpcodes(): array
             } elseif ($j < $bj) {
                 $tag = self::OP_INS;
             } else {
-                $tag = 0;
+                $tag = self::OP_NOP;
             }
 
             if ($tag) {