diff --git a/.gitignore b/.gitignore
index ae3c172..70a2b82 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1 @@
-/bin/
+/bin/joj3
diff --git a/Dockerfile b/Dockerfile
index a7e8fa4..b2d4b91 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,19 +2,6 @@
 
 FROM focs.ji.sjtu.edu.cn:5000/gitea/runner-images:ubuntu-latest
 
-# install elm
-RUN curl -L -o elm.gz https://mirror.ghproxy.com/https://github.com/elm/compiler/releases/download/0.19.1/binary-for-linux-64-bit.gz \
-    && gunzip elm.gz \
-    && chmod +x elm \
-    && mv elm /usr/local/bin/
-
-# install elm-format
-RUN curl -L -o elm-format.tgz https://mirror.ghproxy.com/https://github.com/avh4/elm-format/releases/download/0.8.7/elm-format-0.8.7-linux-x64.tgz \
-    && tar -xvf elm-format.tgz \
-    && rm elm-format.tgz \
-    && chmod +x elm-format \
-    && mv elm-format /usr/local/bin/
-
 # install joint-teapot
 RUN pip install git+https://mirror.ghproxy.com/https://github.com/BoYanZh/Joint-Teapot
 
diff --git a/README.md b/README.md
index 1353ab2..3126df8 100644
--- a/README.md
+++ b/README.md
@@ -6,4 +6,4 @@ Check <https://gitea.com/gitea/runner-images> for information about base images.
 
 ## `/bin` directory
 
-Currently, we have placed various binary files in the `/bin` directory that cannot be publicly downloaded. These files include `dummy`, `healthcheck`, and `joj3` for now.
+Put `joj3` binary in it.
diff --git a/bin/.gitkeep b/bin/.gitkeep
new file mode 100644
index 0000000..e69de29