diff --git a/python/requirements/ml/rllib-requirements.txt b/python/requirements/ml/rllib-requirements.txt
index 86be169696ea..2c71abe19711 100644
--- a/python/requirements/ml/rllib-requirements.txt
+++ b/python/requirements/ml/rllib-requirements.txt
@@ -1,7 +1,7 @@
 # For auto-generating an env-rendering Window.
 pyglet==1.5.15
 imageio-ffmpeg==0.4.5
-onnx==1.15.0; sys_platform != 'darwin' or platform_machine != 'arm64'
+onnx==1.21.0; sys_platform != 'darwin' or platform_machine != 'arm64'
 onnxruntime==1.18.0; sys_platform != 'darwin' or platform_machine != 'arm64'
 rich==13.3.2
 # Msgpack checkpoint stuff.