diff --git a/library/Icingadb/Data/CsvResultSet.php b/library/Icingadb/Data/CsvResultSet.php
index cab6aec1..510db5cc 100644
--- a/library/Icingadb/Data/CsvResultSet.php
+++ b/library/Icingadb/Data/CsvResultSet.php
@@ -14,7 +14,10 @@ class CsvResultSet extends ResultSet
 {
     protected $isCacheDisabled = true;
 
-    public function current()
+    /**
+     * @return array<string, ?string>
+     */
+    public function current(): array
     {
         return $this->extractKeysAndValues(parent::current());
     }
diff --git a/library/Icingadb/Data/JsonResultSet.php b/library/Icingadb/Data/JsonResultSet.php
index f174e21d..b74effc6 100644
--- a/library/Icingadb/Data/JsonResultSet.php
+++ b/library/Icingadb/Data/JsonResultSet.php
@@ -15,7 +15,10 @@ class JsonResultSet extends ResultSet
 {
     protected $isCacheDisabled = true;
 
-    public function current()
+    /**
+     * @return array<string, ?string>
+     */
+    public function current(): array
     {
         return $this->createObject(parent::current());
     }