diff --git a/action.yml b/action.yml
index 0a4c23b..db6752f 100644
--- a/action.yml
+++ b/action.yml
@@ -40,7 +40,9 @@ runs:
         # We *do not* want to record and reuse the target directory path
         # across different git commits, since it may be at a different location
         # in different commits.
-        git checkout "${{ inputs.version-tag-prefix }}$("$GITHUB_ACTION_PATH/find_comparison_version.sh" "$PACKAGE_NAME")"
+        export COMPARISON_TAG="${{ inputs.version-tag-prefix }}$("$GITHUB_ACTION_PATH/find_comparison_version.sh" "$PACKAGE_NAME")"
+        git fetch "$COMPARISON_TAG"
+        git checkout "$COMPARISON_TAG"
         cargo +nightly rustdoc -- -Zunstable-options --output-format json
         mv "$(cargo metadata --format-version 1 | jq -r .target_directory)/doc/$PACKAGE_NAME_WITH_UNDERSCORES.json" /tmp/baseline.json