diff --git a/ci/request-reviews/request-reviews.sh b/ci/request-reviews/request-reviews.sh
index a70a95a65b3a..8a3d78a50d5f 100755
--- a/ci/request-reviews/request-reviews.sh
+++ b/ci/request-reviews/request-reviews.sh
@@ -60,10 +60,9 @@ git -C "$tmp/nixpkgs.git" remote add fork https://github.com/"$prRepo".git
 git -C "$tmp/nixpkgs.git" config remote.fork.partialclonefilter tree:0
 git -C "$tmp/nixpkgs.git" config remote.fork.promisor true
 
-# This should not conflict with any refs in Nixpkgs
-headRef=refs/remotes/fork/pr
-# Only fetch into a remote ref, because the local ref namespace is used by Nixpkgs, don't want any conflicts
-git -C "$tmp/nixpkgs.git" fetch --no-tags fork "$prBranch":"$headRef"
+# Our local branches mirror Nixpkgs, so make sure to not try to update any to avoid conflicts
+git -C "$tmp/nixpkgs.git" fetch --no-tags fork "$prBranch"
+headRef=$(git -C "$tmp/nixpkgs.git" rev-parse HEAD)
 
 log "Checking correctness of the base branch"
 if ! "$SCRIPT_DIR"/verify-base-branch.sh "$tmp/nixpkgs.git" "$headRef" "$baseRepo" "$baseBranch" "$prRepo" "$prBranch" | tee "$tmp/invalid-base-error" >&2; then