diff --git a/apps/dav/lib/Connector/Sabre/QuirksPlugin.php b/apps/dav/lib/Connector/Sabre/QuirksPlugin.php
index 9a08e1c31108f..918f5025e0e17 100644
--- a/apps/dav/lib/Connector/Sabre/QuirksPlugin.php
+++ b/apps/dav/lib/Connector/Sabre/QuirksPlugin.php
@@ -32,14 +32,14 @@ class QuirksPlugin extends ServerPlugin {
 	/** @var bool */
 	private $isMacOSDavAgent = false;
 
-	/** @psalm-var array{major: string, minor: string, patch: string}  */
-	private $macOSVersion;
+	/** @psalm-var null|array{major: string, minor: string, patch: string}  */
+	private $macOSVersion = null;
 
-	/** @var string */
-	private $macOSAgent;
+	/** @var null|string */
+	private $macOSAgent = null;
 
-	/** @psalm-var array{major: string, minor: null|string, patch: null|string} */
-	private $macOSAgentVersion;
+	/** @psalm-var null|array{major: string, minor: null|string, patch: null|string} */
+	private $macOSAgentVersion = null;
 
 	/**
      * Sets up the plugin.