diff --git a/scripts/klippy-requirements.txt b/scripts/klippy-requirements.txt
index 87e664c6..a25eaa34 100644
--- a/scripts/klippy-requirements.txt
+++ b/scripts/klippy-requirements.txt
@@ -10,3 +10,4 @@ Jinja2==2.11.3
 python-can==3.3.4
 markupsafe==1.1.1
 setuptools==75.6.0 ; python_version >= '3.12' # Needed by python-can
+msgspec==0.19.0 ; python_version >= '3.9'