diff --git a/python/pyproject.toml b/python/pyproject.toml
index 672bd335e..0e5514838 100644
--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -49,7 +49,7 @@ runtime_common = [
     "timm==1.0.16",
     "uvicorn",
     "uvloop",
-    "xgrammar==0.1.20",
+    "xgrammar==0.1.21",
 ]
 
 srt = [