diff --git a/src/network/mcpe/auth/ProcessLoginTask.php b/src/network/mcpe/auth/ProcessLoginTask.php
index eab7cf8be..c65203613 100644
--- a/src/network/mcpe/auth/ProcessLoginTask.php
+++ b/src/network/mcpe/auth/ProcessLoginTask.php
@@ -138,6 +138,9 @@ class ProcessLoginTask extends AsyncTask{
 
 			//First link, check that it is self-signed
 			$currentPublicKey = $headers->x5u;
+		}elseif($headers->x5u !== $currentPublicKey){
+			//Fast path: if the header key doesn't match what we expected, the signature isn't going to validate anyway
+			throw new VerifyLoginException("%pocketmine.disconnect.invalidSession.badSignature");
 		}
 
 		$derPublicKeySerializer = new DerPublicKeySerializer();