diff --git a/src/oss/langchain/messages.mdx b/src/oss/langchain/messages.mdx
index d6269faad..2da3a021b 100644
--- a/src/oss/langchain/messages.mdx
+++ b/src/oss/langchain/messages.mdx
@@ -1024,7 +1024,7 @@ for your chosen model for specifics.
     const message = new HumanMessage({
       content: [
         { type: "text", text: "Describe the content of this document." },
-        { type: "file", source_type: "url", url: "https://example.com/path/to/document.pdf" },
+        { type: "file", source_type: "url", url: "https://example.com/path/to/document.pdf", mime_type: "application/pdf" },
       ],
     });
 
@@ -1036,6 +1036,7 @@ for your chosen model for specifics.
           type: "file",
           source_type: "base64",
           data: "AAAAIGZ0eXBtcDQyAAAAAGlzb21tcDQyAAACAGlzb2...",
+          mime_type: "application/pdf",
         },
       ],
     });