diff --git a/4.2/docker-entrypoint.sh b/4.2/docker-entrypoint.sh
index 2d5d209999..61e6af90fa 100755
--- a/4.2/docker-entrypoint.sh
+++ b/4.2/docker-entrypoint.sh
@@ -311,9 +311,8 @@ if [ "$originalArgOne" = 'mongod' ]; then
 			sleep 1
 		done
 
+		rootAuthDatabase='admin'
 		if [ "$MONGO_INITDB_ROOT_USERNAME" ] && [ "$MONGO_INITDB_ROOT_PASSWORD" ]; then
-			rootAuthDatabase='admin'
-
 			"${mongo[@]}" "$rootAuthDatabase" <<-EOJS
 				db.createUser({
 					user: $(_js_escape "$MONGO_INITDB_ROOT_USERNAME"),
@@ -325,6 +324,16 @@ if [ "$originalArgOne" = 'mongod' ]; then
 
 		export MONGO_INITDB_DATABASE="${MONGO_INITDB_DATABASE:-test}"
 
+		if [ "$MONGO_USERNAME" ] && [ "$MONGO_PASSWORD" ]; then
+			"${mongo[@]}" "$rootAuthDatabase" <<-EOJS
+			db.createUser({
+			    user: $(_js_escape "$MONGO_USERNAME"),
+			    pwd: $(_js_escape "$MONGO_PASSWORD"),
+			    roles: [ { role: 'readWrite', db: $(_js_escape "$MONGO_INITDB_DATABASE") } ]
+			})
+		    EOJS
+		fi
+
 		echo
 		for f in /docker-entrypoint-initdb.d/*; do
 			case "$f" in