diff --git a/src/Tag/ListTag.php b/src/Tag/ListTag.php
index f537e8e..5076f51 100644
--- a/src/Tag/ListTag.php
+++ b/src/Tag/ListTag.php
@@ -22,6 +22,10 @@ public function writeContent(Writer $writer): static
     {
         $writer->getSerializer()->writeByte($this->contentTagType);
         if ($this->isRaw()) {
+            if($this->rawContentFormat !== $writer->getFormat()) {
+                throw new Exception("Cannot change format of raw list tag");
+            }
+
             $writer->getSerializer()->writeLengthPrefix($this->rawContentLength);
             $writer->write($this->rawContent);
         } else {