diff --git a/Dockerfile b/Dockerfile
index 31fc0b8..513f0a7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@ FROM public.ecr.aws/sam/build-ruby3.2:latest-x86_64
 RUN set -eux; \
     yum install -y build-essential curl openssl-devel; \
     yum install git; \
-    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | bash -s -- -y --profile minimal; \
+    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | bash -s -- -y --profile minimal --default-toolchain 1.85.0; \
     yum clean all; \
     rm -rf /var/cache/yum