diff --git a/.claude/skills/port-pr/SKILL.md b/.claude/skills/port-pr/SKILL.md
index 4fe0b391..dcd3eb04 100644
--- a/.claude/skills/port-pr/SKILL.md
+++ b/.claude/skills/port-pr/SKILL.md
@@ -32,14 +32,17 @@ gh issue view <ISSUE> --json title,body,labels
 ## Step 2 — Understand the source change
 
 ```bash
-gh pr view <PR> --repo sillsdev/machine --json title,body,files,commits
+gh pr view <PR> --repo sillsdev/machine --json title,body,files,commits,mergeCommit
 gh pr diff <PR> --repo sillsdev/machine
 ```
 
-Read the full diff. For each changed C# file, open the corresponding file(s) in
-`../machine` to understand the surrounding context, and identify the Python counterpart
-(see mapping below). Read the existing Python code you're about to change so the port
-matches local idiom.
+Read the full diff. For each changed C# file, read the corresponding file(s) in
+`../machine` as of the merge commit, with `git -C ../machine show <mergeCommit>:<path>`,
+to understand the surrounding context. The working tree may have moved on since the PR
+merged. First check the commit with `git -C ../machine cat-file -e <mergeCommit>`. If it
+fails, the clone predates the merge: run `git -C ../machine fetch`. Identify the Python
+counterpart (see mapping below). Read the existing Python code you're about to change so
+the port matches local idiom.
 
 Note: not every change ports. Skip C#-only concerns (`.csproj`/`.sln`/`Directory.*.props`,
 `AssemblyInfo`, `omnisharp.json`, csharpier/editorconfig formatting, NuGet packaging).
diff --git a/.github/workflows/claude.yml b/.github/workflows/claude.yml
index 7a4cfd18..dee8cc3e 100644
--- a/.github/workflows/claude.yml
+++ b/.github/workflows/claude.yml
@@ -70,6 +70,11 @@ jobs:
       - name: Install dependencies
         run: poetry install --no-interaction --all-extras
 
+      # port-pr reads the C# source from a sibling clone, as of each source PR's merge
+      # commit, so it needs full history. Outside the workspace, black and flake8 skip it.
+      - name: Clone sillsdev/machine
+        run: git clone https://github.com/sillsdev/machine.git ../machine
+
       - name: Run Claude Code
         id: claude
         uses: anthropics/claude-code-action@v1
@@ -83,7 +88,8 @@ jobs:
           # The action's own prompt ends an issue run with a "Create a PR" link; the
           # appended prompt has Claude open the pull request itself.
           claude_args: >-
-            --allowedTools "Bash(gh pr create:*),Bash(gh pr view:*),Bash(gh pr diff:*),Bash(gh issue view:*),Bash(git log:*),Bash(git blame:*),Bash(git show:*),Bash(git diff:*),Bash(git status:*),Bash(poetry run:*),Bash(./local_check.sh:*)"
+            --add-dir ../machine
+            --allowedTools "Bash(gh pr create:*),Bash(gh pr view:*),Bash(gh pr diff:*),Bash(gh issue view:*),Bash(git log:*),Bash(git blame:*),Bash(git show:*),Bash(git diff:*),Bash(git status:*),Bash(git -C ../machine show:*),Bash(git -C ../machine cat-file:*),Bash(git -C ../machine log:*),Bash(git -C ../machine blame:*),Bash(poetry run:*),Bash(./local_check.sh:*)"
             --append-system-prompt "When invoked on an issue and you change code, open the pull request yourself once your commits are pushed: gh pr create --base main --head <your branch>. Post its link in your comment in place of a Create a PR link. Write the title and body with the pr-authoring skill, and put Closes #<issue number> in the body. Before opening it, run ./local_check.sh --agent-strict and report its result in the body. Dependencies are already installed, and you work on the branch this action created: where a skill such as port-pr says to install, create or switch branches, or push, commit on the current branch and push it the way these instructions say."
           # See https://github.com/anthropics/claude-code-action/blob/main/docs/usage.md
           # or https://code.claude.com/docs/en/cli-reference for available options