diff --git a/src/Prometheus/Storage/Redis.php b/src/Prometheus/Storage/Redis.php
index 0a4096e..3550992 100644
--- a/src/Prometheus/Storage/Redis.php
+++ b/src/Prometheus/Storage/Redis.php
@@ -198,7 +198,7 @@ private function ensureOpenConnection(): void
         $this->connectToServer();
         $authParams = [];
 
-        if (isset($this->options['user'])) {
+        if (isset($this->options['user']) && $this->options['user'] !== '') {
             $authParams[] = $this->options['user'];
         }
 
diff --git a/src/Prometheus/Storage/RedisNg.php b/src/Prometheus/Storage/RedisNg.php
index 865a07e..0ef8793 100644
--- a/src/Prometheus/Storage/RedisNg.php
+++ b/src/Prometheus/Storage/RedisNg.php
@@ -198,7 +198,7 @@ private function ensureOpenConnection(): void
         $this->connectToServer();
         $authParams = [];
 
-        if (isset($this->options['user'])) {
+        if (isset($this->options['user']) && $this->options['user'] !== '') {
             $authParams[] = $this->options['user'];
         }