diff --git a/src/Core/Cache.php b/src/Core/Cache.php
index 2f16e3a38d..7c73c4270e 100644
--- a/src/Core/Cache.php
+++ b/src/Core/Cache.php
@@ -341,7 +341,7 @@ abstract class Cache
                 }
             };
             $res = $get();
-            if (\is_null($res)) {
+            if (empty($res)) {
                 self::setHashMap($map_key, $calculate_map(), $pool);
                 $res = $get();
             }