diff --git a/src/Entity/Client.php b/src/Entity/Client.php
index b5943a8..f5259fc 100644
--- a/src/Entity/Client.php
+++ b/src/Entity/Client.php
@@ -20,9 +20,9 @@ class Client implements ClientEntityInterface
      * @param bool $isConfidential
      */
     public function __construct(
-        string $identifier = null,
-        string $name = null,
-        array $redirectUri = null,
+        ?string $identifier = null,
+        ?string $name = null,
+        ?array $redirectUri = null,
         bool $isConfidential = false
     ) {
         $this->isConfidential = $isConfidential;
diff --git a/src/Server.php b/src/Server.php
index 4ebd491..6e098d1 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -59,9 +59,9 @@ final public function respondToDynamicClientRegistrationRequest(Request $request
 
     final public function respondToAuthorizationRequest(
         Request $request,
-        User $user = null,
-        bool $authorizationApproved = null,
-        callable $callback = null
+        ?User $user = null,
+        ?bool $authorizationApproved = null,
+        ?callable $callback = null
     ) : Response {
         $serverConfig = $this->config->getServer();
         $authorizationServer = $this->authorizationServer;
diff --git a/src/TokenGenerator.php b/src/TokenGenerator.php
index 55ec8c2..55308e5 100644
--- a/src/TokenGenerator.php
+++ b/src/TokenGenerator.php
@@ -190,7 +190,6 @@ public function addIdTokenToResponse($response, $clientId, $subject, $nonce, $pr
                 if (isset($body['error'])) {
                     return $response;
                 }
-                    
                 $accessToken = $this->generateAccessToken($clientId, $subject);
                 $accessToken = $this->bindDpop($dpop, $accessToken);
                 $accessToken = $this->signToken($accessToken);
diff --git a/src/WAC.php b/src/WAC.php
index 68b1aad..07da935 100644
--- a/src/WAC.php
+++ b/src/WAC.php
@@ -53,10 +53,10 @@ public function isAllowed($request, $webId, $origin=false, $allowedOrigins=[]) {
 		$uri = $request->getUri();
 		$parentUri = $this->getParentUri($uri);
 
-	// @FIXME: $origin can be anything at this point, null, string, array, bool
-	//	 This causes trouble downstream where an unchecked `parse_url($origin)['host'];` occurs
+		// @FIXME: $origin can be anything at this point, null, string, array, bool
+		//	 This causes trouble downstream where an unchecked `parse_url($origin)['host'];` occurs
 
-	foreach ($requestedGrants as $requestedGrant) {
+		foreach ($requestedGrants as $requestedGrant) {
 			switch ($requestedGrant['type']) {
 				case "resource":
 					if ($this->isPublicGranted($requestedGrant['grants'], $uri)) {
@@ -141,9 +141,9 @@ private function isOriginGranted($requestedGrants, $uri, $origin, $allowedOrigin
 		) {
 			return true;
 		}
-		//error_log("REQUESTED GRANT: " . join(" or ", $requestedGrants) . " on $uri");
+		// error_log("REQUESTED GRANT: " . join(" or ", $requestedGrants) . " on $uri");
 		$grants = $this->getOriginGrants($uri, $origin);
-		//error_log("GRANTED GRANTS for origin $origin: " . json_encode($grants));
+		// error_log("GRANTED GRANTS for origin $origin: " . json_encode($grants));
 		return $this->checkGrants($requestedGrants, $uri, $grants);
 	}
 
@@ -307,14 +307,13 @@ private function getAclPath($path) {
 
 		foreach ($aclOptions as $aclPath) {
 			if (
-				$this->filesystem->has($aclPath)
-		&& $this->filesystem->read($aclPath) !== false
+				$this->filesystem->has($aclPath) && $this->filesystem->read($aclPath) !== false
 			) {
 				return $aclPath;
 			}
 		}
 
-		//error_log("Seeking .acl from $path");
+		// error_log("Seeking .acl from $path");
 		// see: https://github.com/solid/web-access-control-spec#acl-inheritance-algorithm
 		// check for acl:default predicate, if not found, continue searching up the directory tree
 		return $this->getParentAcl($path);
@@ -323,10 +322,10 @@ private function normalizePath($path) {
 		return preg_replace("|//|", "/", $path);
 	}
 	private function getParentAcl($path) {
-		//error_log("GET PARENT ACL $path");
-		if ($this->filesystem->has($path.'/.acl')) {
-			//error_log("CHECKING ACL FILE ON $path/.acl");
-			return $path . "/.acl";
+		// error_log("GET PARENT ACL $path");
+		if ($this->filesystem->has($this->normalizePath($path.'/.acl'))) {
+			// error_log("CHECKING ACL FILE ON $path/.acl");
+			return $this->normalizePath($path . "/.acl");
 		}
 		$parent = dirname($path);
 		if ($parent == $path) {