diff --git a/src/Utils/Callback.php b/src/Utils/Callback.php
index 49dddfa7d..496c1e7ab 100644
--- a/src/Utils/Callback.php
+++ b/src/Utils/Callback.php
@@ -110,7 +110,7 @@ public static function toReflection($callable): \ReflectionMethod|\ReflectionFun
 	 */
 	public static function isStatic(callable $callable): bool
 	{
-		return is_array($callable) ? is_string($callable[0]) : is_string($callable);
+		return is_string(is_array($callable) ? $callable[0] : $callable);
 	}