diff --git a/tools/run_tests/helper_scripts/build_python_msys2.sh b/tools/run_tests/helper_scripts/build_python_msys2.sh
index 4c54f1c4727..f388b4bf965 100644
--- a/tools/run_tests/helper_scripts/build_python_msys2.sh
+++ b/tools/run_tests/helper_scripts/build_python_msys2.sh
@@ -15,7 +15,7 @@
 
 set -ex
 
-BUILD_PYTHON=`realpath "$(dirname $0)/build_python.sh"`
+BUILD_PYTHON=$(realpath "$(dirname "$0")/build_python.sh")
 export MSYSTEM=$1
 shift 1
-bash --login $BUILD_PYTHON "$@"
+bash --login "$BUILD_PYTHON" "$@"