diff --git a/Dockerfile b/Dockerfile
index 6171982..a8f7083 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,27 +1,26 @@
-FROM ubuntu:latest
+FROM ubuntu:22.04
+SHELL ["/bin/bash", "-c"]
 ENV DEBIAN_FRONTEND=noninteractive
-# Non-root user setup
 ARG USERNAME=root
-ARG TESTER_HOME=/root
-
-RUN apt-get update -y
-RUN apt-get upgrade -y
-RUN apt-get install -y sudo git vim wget python-is-python3
-
-# Setup ORFS under ~
-RUN mkdir -p $TESTER_HOME
-WORKDIR $TESTER_HOME
-RUN git clone --recursive https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts
-WORKDIR $TESTER_HOME/OpenROAD-flow-scripts
-ENV SUDO_USER=$USERNAME
-RUN sudo ./setup.sh
-RUN ./build_openroad.sh --local
-# test ORFS build
-SHELL ["/bin/bash", "-c"]
-RUN source ./env.sh && yosys -help && openroad -help && cd flow && make -j $(nproc)
+ARG USER_HOME=/root
+ARG ORFS_REF=067099e79f308b77cb7f031f37d2f9ca2ac25b7b
 
-# Install bazelisk as bazel
-RUN sudo wget https://github.com/bazelbuild/bazelisk/releases/download/v1.19.0/bazelisk-linux-amd64 -O /usr/local/bin/bazel
-RUN sudo chmod +x /usr/local/bin/bazel
+RUN apt-get update -y && \
+    apt-get upgrade -y && \
+	apt-get install -y sudo git vim wget python-is-python3 && \
+    # Setup ORFS under ~
+    mkdir -p $USER_HOME && \
+	cd $USER_HOME && \
+	git clone --recursive https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts && \
+    cd $USER_HOME/OpenROAD-flow-scripts && \
+	git checkout $ORFS_REF && \
+	export SUDO_USER=$USERNAME && \
+    sudo ./setup.sh && \
+    ./build_openroad.sh --local && \
+    # test ORFS build
+	source ./env.sh && yosys -help && openroad -help && cd flow && make -j $(nproc) && \
+    # Install bazelisk as bazel
+	sudo wget https://github.com/bazelbuild/bazelisk/releases/download/v1.19.0/bazelisk-linux-amd64 -O /usr/local/bin/bazel && \
+	sudo chmod +x /usr/local/bin/bazel
 
-WORKDIR $TESTER_HOME
+WORKDIR $USER_HOME