diff --git a/.evergreen/release-build-vars.sh b/.evergreen/release-build-vars.sh
index 81ffac392..1ee75ae0e 100644
--- a/.evergreen/release-build-vars.sh
+++ b/.evergreen/release-build-vars.sh
@@ -13,7 +13,7 @@ CRATE_VERSION=$(cargo metadata --format-version=1 --no-deps | jq --raw-output '.
 rm secrets-export.sh
 
 PAPERTRAIL_PRODUCT="rust-driver"
-if [[ "${DRY_RUN}" == "yes" ]]; then
+if [[ "${DRY_RUN:-}" == "yes" ]]; then
   PAPERTRAIL_PRODUCT="rust-driver-testing"
 fi