diff --git a/backend/requirements-dev.txt b/backend/requirements-dev.txt
new file mode 100644
index 0000000..ae47c30
--- /dev/null
+++ b/backend/requirements-dev.txt
@@ -0,0 +1,9 @@
+# Development and load-test dependencies.
+# NOT installed by the production Dockerfile.
+# Install separately on the host or in a dedicated venv via:
+#   pip install -r backend/requirements-dev.txt
+
+-r requirements.txt
+
+# Load testing (Phase 6 — D-04)
+locust>=2.34.0