diff --git a/steamcmd/proton/Dockerfile b/steamcmd/proton/Dockerfile
index 58d144e..e389165 100644
--- a/steamcmd/proton/Dockerfile
+++ b/steamcmd/proton/Dockerfile
@@ -3,7 +3,7 @@ FROM debian:bookworm-slim
 LABEL author="Tara Piccari" maintainer="tarapiccari@gmail.com"
 LABEL upstream="https://github.com/pelican-eggs/yolks"
 
-ENV PROTON_VERSION=9.13
+ENV PROTON_VERSION=9-13
 
 ## install required packages
 RUN         dpkg --add-architecture i386