diff --git a/.buildkite/scripts/upload-wheels.sh b/.buildkite/scripts/upload-wheels.sh
index 2eaa91c040..0ac8fdd45b 100644
--- a/.buildkite/scripts/upload-wheels.sh
+++ b/.buildkite/scripts/upload-wheels.sh
@@ -81,7 +81,7 @@ else
     alias_arg=""
 fi
 
-$PYTHON .buildkite/scripts/generate-nightly-index.py --version "$SUBPATH" --current-objects "$obj_json" --output-dir "$INDICES_OUTPUT_DIR" $alias_arg
+$PYTHON pip install regex && .buildkite/scripts/generate-nightly-index.py --version "$SUBPATH" --current-objects "$obj_json" --output-dir "$INDICES_OUTPUT_DIR" $alias_arg
 
 # copy indices to /<commit>/ unconditionally
 echo "Uploading indices to $S3_COMMIT_PREFIX"