diff --git a/libs/core/langchain_core/runnables/graph_mermaid.py b/libs/core/langchain_core/runnables/graph_mermaid.py
index b0e7f3dd5de..c9b3025bc85 100644
--- a/libs/core/langchain_core/runnables/graph_mermaid.py
+++ b/libs/core/langchain_core/runnables/graph_mermaid.py
@@ -2,7 +2,7 @@ import asyncio
 import base64
 import re
 from dataclasses import asdict
-from typing import Optional
+from typing import Literal, Optional
 
 from langchain_core.runnables.graph import (
     CurveStyle,
@@ -306,6 +306,7 @@ def _render_mermaid_using_api(
     mermaid_syntax: str,
     output_file_path: Optional[str] = None,
     background_color: Optional[str] = "white",
+    file_type: Optional[Literal["jpeg", "png", "webp"]] = "png",
 ) -> bytes:
     """Renders Mermaid graph using the Mermaid.INK API."""
     try:
@@ -329,7 +330,8 @@ def _render_mermaid_using_api(
             background_color = f"!{background_color}"
 
     image_url = (
-        f"https://mermaid.ink/img/{mermaid_syntax_encoded}?bgColor={background_color}"
+        f"https://mermaid.ink/img/{mermaid_syntax_encoded}"
+        f"?type={file_type}&bgColor={background_color}"
     )
     response = requests.get(image_url, timeout=10)
     if response.status_code == 200: