diff --git a/README.md b/README.md
index 04ea491..6bc9bd4 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ Base images for Coder workspaces.
 
 | Image | Tag | Contents |
 |-------|-----|----------|
-| Base | `:base` | Ubuntu Noble + bash, bash-completion, git, curl, Node.js 24, gh CLI, tea CLI, ripgrep, fd-find, tmux, build-essential, age, sops, ssh-to-age |
+| Base | `:base` | Ubuntu Noble + bash, bash-completion, git, curl, Node.js 24, gh CLI, tea CLI, ripgrep, fd-find, tmux, build-essential, age, sops, ssh-to-age, lsof |
 | DevOps | `:devops` | Base + Terraform, Packer, tflint, azcopy |
 
 ## Usage
diff --git a/images/base/Dockerfile b/images/base/Dockerfile
index aabbbe4..44f3ac7 100644
--- a/images/base/Dockerfile
+++ b/images/base/Dockerfile
@@ -20,6 +20,7 @@ apt-get install -y --no-install-recommends \
     git-lfs \
     iproute2 \
     jq \
+    lsof \
     locales \
     openssh-client \
     sudo