diff --git a/Dockerfile.simple b/Dockerfile.simple
index 55421e1..ce04caa 100644
--- a/Dockerfile.simple
+++ b/Dockerfile.simple
@@ -6,11 +6,11 @@ ARG SERVICE_NAME
 FROM ci.nxtgauge.com/admin/rust:alpine AS builder
 ARG SERVICE_NAME
 
-# Install build deps + rust toolchain (Alpine-packaged Rust lacks proc-macro support)
+# The official rust:alpine base already provides a full rustup-installed
+# toolchain (unlike Alpine's apk-packaged rust, which lacks proc-macro
+# support) - just add build deps and the musl target.
 RUN apk add --no-cache curl ca-certificates bash build-base musl-dev pkgconfig openssl-dev openssl-libs-static
 RUN update-ca-certificates
-RUN curl -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal --default-toolchain stable
-ENV PATH="/root/.cargo/bin:${PATH}"
 RUN rustup target add x86_64-unknown-linux-musl
 
 WORKDIR /app