diff --git a/.github/workflows/static.yml b/.github/workflows/static.yml
index a19492b..0089206 100644
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@@ -14,7 +14,9 @@ jobs:
           composer update --no-interaction --prefer-dist --optimize-autoloader
 
       - name: PHPStan
-        uses: docker://oskarstark/phpstan-ga:0.12.44
+        uses: docker://oskarstark/phpstan-ga:0.12.48
+        env:
+          REQUIRE_DEV: true
         with:
           entrypoint: /composer/vendor/bin/phpstan
           args: analyze --no-progress
@@ -28,7 +30,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: PHP-CS-Fixer
-        uses: OskarStark/php-cs-fixer-ga@2.16.4.1
+        uses: OskarStark/php-cs-fixer-ga@2.16.4
         with:
           args: --dry-run --diff-format udiff
 
@@ -40,6 +42,8 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Psalm
-        uses: psalm/psalm-github-actions@master
+        uses: docker://vimeo/psalm-github-actions:3.17.2
+        env:
+          REQUIRE_DEV: true
         with:
           args: --no-progress --show-info=false --stats
diff --git a/composer.json b/composer.json
index d8772f8..c016cb9 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
     "require-dev": {
         "phpunit/phpunit": "^7.5",
         "php-http/psr7-integration-tests": "^1.0",
-        "http-interop/http-factory-tests": "dev-master",
+        "http-interop/http-factory-tests": "^0.8",
         "symfony/error-handler": "^4.4"
     },
     "provide": {
diff --git a/tests/UriTest.php b/tests/UriTest.php
index d5f52fa..bb165e8 100644
--- a/tests/UriTest.php
+++ b/tests/UriTest.php
@@ -126,12 +126,22 @@ public function testWithPortCannotBeNegative()
         (new Uri())->withPort(-1);
     }
 
-    public function testParseUriPortCannotBeZero()
+    public function testParseUriPortCannotBeNegative()
     {
         $this->expectException(\InvalidArgumentException::class);
         $this->expectExceptionMessage('Unable to parse URI');
 
-        new Uri('//example.com:0');
+        new Uri('//example.com:-1');
+    }
+
+    public function testParseUriPortCanBeZero()
+    {
+        if (version_compare(PHP_VERSION, '7.4.12') < 0) {
+            self::markTestSkipped('Skipping this on low PHP versions.');
+        }
+
+        $uri = new Uri('//example.com:0');
+        $this->assertEquals(0, $uri->getPort());
     }
 
     public function testSchemeMustHaveCorrectType()