diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
new file mode 100644
index 0000000..7bebcfd
--- /dev/null
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,5 @@
+FROM mcr.microsoft.com/devcontainers/javascript-node:1-18-bullseye
+
+RUN apt update -y \
+    && apt install -y --no-install-recommends shellcheck \
+    && rm -rf /var/lib/apt/lists/*
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 8aac3ae..616e376 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -1,5 +1,5 @@
 {
-  "image": "mcr.microsoft.com/devcontainers/javascript-node:1-18-bullseye",
+  "dockerFile": "Dockerfile",
   "customizations": {
     "vscode": {
       "settings": {