diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9c0549931..858c9a8c8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,6 +12,8 @@ jobs:
 
     - name: Checkout
       uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
 
     - name: Set up PR environment
       if: github.event.number != null
diff --git a/scripts/check-pr.sh b/scripts/check-pr.sh
index f5db3ab30..2b6784a40 100644
--- a/scripts/check-pr.sh
+++ b/scripts/check-pr.sh
@@ -49,7 +49,7 @@ function check_diff {
   local line
   local entry
 
-  git_diff=$(git diff --name-status --find-copies-harder --diff-filter=AC --relative=pages/ master)
+  git_diff=$(git diff --name-status --find-copies-harder --diff-filter=AC --relative=pages/ remotes/origin/master)
 
   if [ -n "$git_diff" ]; then
     echo -e "Check PR: git diff:\n$git_diff" >&2