diff --git a/tools/robustness-job.sh b/tools/robustness-job.sh
index 27c958225..5f4f6eace 100755
--- a/tools/robustness-job.sh
+++ b/tools/robustness-job.sh
@@ -112,6 +112,7 @@ if [[ "${ENGINE_MODE}" = SERVER ]]; then
 fi
 
 # Source any pre-test rc files if provided
+TEST_RC="${TEST_RC:-}"
 if [[ -f ${TEST_RC} ]]; then
     source ${TEST_RC}
 fi