diff --git a/Dockerfile b/Dockerfile
index 0474758..a722360 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -38,7 +38,7 @@ ENV PATH=/home/rust/.cargo/bin:/usr/local/musl/bin:/usr/local/bin:/usr/bin:/bin
 # interact with the user or fool around with TTYs.  We also set the default
 # `--target` to musl so that our users don't need to keep overriding it
 # manually.
-RUN curl https://sh.rustup.rs -sSf | sed 's,run "$_file" < /dev/tty,run "$_file" -y,' | sh && \
+RUN curl https://sh.rustup.rs -sSf | sh -s -- -y && \
     rustup default stable && \
     rustup target add x86_64-unknown-linux-musl
 ADD cargo-config.toml /home/rust/.cargo/config