diff --git a/scripts/build-packages-dist.sh b/scripts/build-packages-dist.sh
index b398af07d1..ac1d21f96c 100755
--- a/scripts/build-packages-dist.sh
+++ b/scripts/build-packages-dist.sh
@@ -56,9 +56,9 @@ buildTargetPackages "$LEGACY_TARGETS" "dist/packages-dist" "legacy" "Production"
 # snapshots.
 # This logic matches what we use in the .circleci/config.yml file to short-
 # circuit execution of the publish-packages job.
-[[  -v CIRCLE_PR_NUMBER
-    || "$CIRCLE_PROJECT_USERNAME" != "angular"
-    || "$CIRCLE_PROJECT_REPONAME" != "angular"
+[[  "${CIRCLE_PR_NUMBER-}" != ""
+    || "${CIRCLE_PROJECT_USERNAME-}" != "angular"
+    || "${CIRCLE_PROJECT_REPONAME-}" != "angular"
 ]] && exit 0
 
 IVY_JIT_TARGETS=`bazel query --output=label 'attr("tags", "\[.*ivy-jit.*\]", //packages/...) intersect kind(".*_package", //packages/...)'`