diff --git a/ci/docker-rust-nightly/Dockerfile b/ci/docker-rust-nightly/Dockerfile
index 1dacf11e64..2f0e2c0573 100644
--- a/ci/docker-rust-nightly/Dockerfile
+++ b/ci/docker-rust-nightly/Dockerfile
@@ -4,6 +4,6 @@ RUN cargo install --force clippy cargo-cov && \
     echo deb http://ftp.debian.org/debian stretch-backports main >> /etc/apt/sources.list && \
     apt update && \
     apt install -y \
-      llvm-6.0
+      llvm-6.0 \
       && \
     rm -rf /var/lib/apt/lists/*