diff --git a/.github/workflows/static.yml b/.github/workflows/static.yml
index b2f69cf..6530f18 100644
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@@ -31,6 +31,6 @@ jobs:
         uses: actions/checkout@v2
 
       - name: PHP-CS-Fixer
-        uses: docker://oskarstark/php-cs-fixer-ga
+        uses: docker://oskarstark/php-cs-fixer-ga:2.19.0
         with:
           args: --dry-run --diff-format udiff
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b36da2d..2c580bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [1.11.1] - 2021-05-24
+
+- Support GuzzleHttp/Psr7 version 2.0 in the (deprecated) GuzzleUriFactory.
+
 ## [1.11.0] - 2020-02-01
 
 - Migrated from `zendframework/zend-diactoros` to `laminas/laminas-diactoros`.
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 9c95e48..40013ca 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -11,17 +11,17 @@ parameters:
 			path: src/Authentication/Header.php
 
 		-
-			message: "#^Property Http\\\\Message\\\\Authentication\\\\QueryParam\\:\\:\\$params type has no value type specified in iterable type array\\.$#"
+			message: "#The Http\\\\Message\\\\Authentication\\\\Matching class is deprecated since version 1.2 and will be removed in 2.0.#"
 			count: 1
-			path: src/Authentication/QueryParam.php
+			path: src/Authentication/Matching.php
 
 		-
-			message: "#^Method Http\\\\Message\\\\Authentication\\\\QueryParam\\:\\:__construct\\(\\) has parameter \\$params with no value type specified in iterable type array\\.$#"
+			message: "#^Property Http\\\\Message\\\\Authentication\\\\QueryParam\\:\\:\\$params type has no value type specified in iterable type array\\.$#"
 			count: 1
 			path: src/Authentication/QueryParam.php
 
 		-
-			message: "#^Parameter \\#2 \\$prefix of function http_build_query expects string, null given\\.$#"
+			message: "#^Method Http\\\\Message\\\\Authentication\\\\QueryParam\\:\\:__construct\\(\\) has parameter \\$params with no value type specified in iterable type array\\.$#"
 			count: 1
 			path: src/Authentication/QueryParam.php
 
@@ -46,7 +46,7 @@ parameters:
 			path: src/Cookie.php
 
 		-
-			message: "#^Parameter \\#2 \\$str2 of function strcasecmp expects string, string\\|null given\\.$#"
+			message: "#^Parameter \\#2 \\$string2 of function strcasecmp expects string, string\\|null given\\.$#"
 			count: 1
 			path: src/Cookie.php
 
@@ -76,7 +76,7 @@ parameters:
 			path: src/Cookie.php
 
 		-
-			message: "#^Parameter \\#1 \\$str of function rtrim expects string, string\\|null given\\.$#"
+			message: "#^Parameter \\#1 \\$string of function rtrim expects string, string\\|null given\\.$#"
 			count: 1
 			path: src/Cookie.php
 
@@ -160,16 +160,6 @@ parameters:
 			count: 2
 			path: src/Encoding/Filter/Chunk.php
 
-		-
-			message: "#^Parameter \\#2 \\$bucket of function stream_bucket_append expects object, resource given\\.$#"
-			count: 2
-			path: src/Encoding/Filter/Chunk.php
-
-		-
-			message: "#^Unreachable statement \\- code above always terminates\\.$#"
-			count: 1
-			path: src/Encoding/Filter/Chunk.php
-
 		-
 			message: "#^Method Http\\\\Message\\\\Encoding\\\\FilteredStream\\:\\:fill\\(\\) has no return typehint specified\\.$#"
 			count: 1
@@ -215,6 +205,11 @@ parameters:
 			count: 1
 			path: src/MessageFactory/SlimMessageFactory.php
 
+		-
+			message: "#The Http\\\\Message\\\\RequestMatcher\\\\RegexRequestMatcher class is deprecated since version 1.2 and will be removed in 2.0.#"
+			count: 1
+			path: src/RequestMatcher/RegexRequestMatcher.php
+
 		-
 			message: "#^Property Http\\\\Message\\\\RequestMatcher\\\\RequestMatcher\\:\\:\\$methods type has no value type specified in iterable type array\\.$#"
 			count: 1
diff --git a/src/Authentication/QueryParam.php b/src/Authentication/QueryParam.php
index 7f95d44..243efef 100644
--- a/src/Authentication/QueryParam.php
+++ b/src/Authentication/QueryParam.php
@@ -38,7 +38,7 @@ public function authenticate(RequestInterface $request)
 
         $params = array_merge($params, $this->params);
 
-        $query = http_build_query($params, null, '&');
+        $query = http_build_query($params, '', '&');
 
         $uri = $uri->withQuery($query);
 
diff --git a/src/UriFactory/GuzzleUriFactory.php b/src/UriFactory/GuzzleUriFactory.php
index b16ca52..e09ac61 100644
--- a/src/UriFactory/GuzzleUriFactory.php
+++ b/src/UriFactory/GuzzleUriFactory.php
@@ -2,7 +2,8 @@
 
 namespace Http\Message\UriFactory;
 
-use GuzzleHttp\Psr7;
+use function GuzzleHttp\Psr7\uri_for;
+use GuzzleHttp\Psr7\Utils;
 use Http\Message\UriFactory;
 
 /**
@@ -19,6 +20,10 @@ final class GuzzleUriFactory implements UriFactory
      */
     public function createUri($uri)
     {
-        return Psr7\uri_for($uri);
+        if (class_exists(Utils::class)) {
+            return Utils::uriFor($uri);
+        }
+
+        return uri_for($uri);
     }
 }