diff --git a/.github/docker/Dockerfile b/.github/docker/Dockerfile
index 80baade..9b650f3 100644
--- a/.github/docker/Dockerfile
+++ b/.github/docker/Dockerfile
@@ -70,3 +70,9 @@ RUN echo 'local({ \
 RUN Rscript -e 'install.packages("pak")'
 COPY install-packages.R /tmp/install-packages.R
 RUN Rscript /tmp/install-packages.R && rm /tmp/install-packages.R
+
+# GitHub Copilot's injected "Prepare Copilot" step uses `set -o pipefail` via
+# `shell: sh`, which dash (Debian's default /bin/sh) doesn't support.  Redirect
+# /bin/sh to bash, which is already installed and is a superset of POSIX sh.
+# Placed last so no apt postinst script can overwrite the symlink during build.
+RUN ln -sf /bin/bash /bin/sh
diff --git a/.github/workflows/copilot-setup-steps.yml b/.github/workflows/copilot-setup-steps.yml
index d5dffcf..7830bdb 100644
--- a/.github/workflows/copilot-setup-steps.yml
+++ b/.github/workflows/copilot-setup-steps.yml
@@ -15,6 +15,7 @@ jobs:
   # The job MUST be called `copilot-setup-steps` or it will not be picked up by Copilot.
   copilot-setup-steps:
     runs-on: ubuntu-latest
+    container: ghcr.io/api2r/pkgskills-ci:release
 
     permissions:
       contents: read
@@ -24,6 +25,7 @@ jobs:
 
       - uses: ./.github/workflows/install
         with:
+          use-container: "true"
           token: ${{ secrets.GITHUB_TOKEN }}
           cache-version: copilot
           needs: build, check, website
diff --git a/NEWS.md b/NEWS.md
index 30d50a2..782bd2a 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,6 @@
 # pkgskills (development version)
 
+* `use_github_copilot()` now installs a container-based `copilot-setup-steps.yml` for faster agent startup (#67).
 * `AGENTS.md` and `tdd-workflow` skill instructions now explicitly explain how to determine the GitHub issue number and warn agents never to guess or invent one (@copilot, #61).
 * `use_agent()` template is reconciled with this package's `AGENTS.md` file (#59).
 * `tdd-workflow` skill now documents `stbl::expect_pkg_error_snapshot()` with an explicit `package` argument instead of a helper-defined version (#51).
diff --git a/inst/templates/workflows/copilot-setup-steps.yml b/inst/templates/workflows/copilot-setup-steps.yml
index e299ee3..fb03545 100644
--- a/inst/templates/workflows/copilot-setup-steps.yml
+++ b/inst/templates/workflows/copilot-setup-steps.yml
@@ -15,6 +15,7 @@ jobs:
   # The job MUST be called `copilot-setup-steps` or it will not be picked up by Copilot.
   copilot-setup-steps:
     runs-on: ubuntu-latest
+    container: ghcr.io/api2r/pkgskills-ci:release
 
     permissions:
       contents: read
@@ -24,6 +25,7 @@ jobs:
 
       - uses: ./.github/workflows/install
         with:
+          use-container: "true"
           token: ${{ secrets.GITHUB_TOKEN }}
           cache-version: copilot
           needs: build, check, website