Make shellcheck happy
diff --git a/tools/run_tests/performance/build_performance.sh b/tools/run_tests/performance/build_performance.sh
index 92d2a7f..0923454 100755
--- a/tools/run_tests/performance/build_performance.sh
+++ b/tools/run_tests/performance/build_performance.sh
@@ -18,7 +18,7 @@
 set -ex
 
 cd "$(dirname "$0")/../../.."
-bazel=`pwd`/tools/bazel
+bazel=$(pwd)/tools/bazel
 
 CONFIG=${CONFIG:-opt}