diff --git a/Makefile b/Makefile
index b9016bfa..157829fc 100644
--- a/Makefile
+++ b/Makefile
@@ -2,9 +2,10 @@
 # Nightscout tests/builds/analysis
 TESTS=tests/*.js
 MONGO_CONNECTION?=mongodb://localhost:27017/test_db
+AUTH_FAIL_DELAY?=50
 CUSTOMCONNSTR_mongo_settings_collection?=test_settings
 CUSTOMCONNSTR_mongo_collection?=test_sgvs
-MONGO_SETTINGS=MONGO_CONNECTION=${MONGO_CONNECTION} \
+MONGO_SETTINGS=AUTH_FAIL_DELAY=${AUTH_FAIL_DELAY} MONGO_CONNECTION=${MONGO_CONNECTION} \
 	CUSTOMCONNSTR_mongo_collection=${CUSTOMCONNSTR_mongo_collection}
 
 # XXX.bewest: Mocha is an odd process, and since things are being
@@ -35,6 +36,7 @@ my.test.env:
 	@echo "CUSTOMCONNSTR_mongo_collection=${CUSTOMCONNSTR_mongo_collection}" >> my.test.env
 	@echo "CUSTOMCONNSTR_mongo_settings_collection=${CUSTOMCONNSTR_mongo_settings_collection}" >> my.test.env
 	@echo "API_SECRET=test-secret-key" >> my.test.env
+	@echo "AUTH_FAIL_DELAY=${AUTH_FAIL_DELAY}" >> my.test.env
 	@echo "INSECURE_USE_HTTP=true" >> my.test.env
 
 coverage: