diff --git a/src/Model/Message/ShowResponse.php b/src/Model/Message/ShowResponse.php
index 9069ccf..0315a24 100644
--- a/src/Model/Message/ShowResponse.php
+++ b/src/Model/Message/ShowResponse.php
@@ -131,7 +131,7 @@ final class ShowResponse implements ApiResponse
         return $this->messageUrl;
     }
 
-    public function getContentIdMap(): ?string
+    public function getContentIdMap(): ?array
     {
         return $this->contentIdMap;
     }