diff --git a/Tests/UriResolverTest.php b/Tests/UriResolverTest.php
index b0c227a..f5ca403 100644
--- a/Tests/UriResolverTest.php
+++ b/Tests/UriResolverTest.php
@@ -84,6 +84,10 @@ public static function provideResolverTests()
 
             ['foo', 'http://localhost?bar=1', 'http://localhost/foo'],
             ['foo', 'http://localhost#bar', 'http://localhost/foo'],
+
+            ['foo:1', 'http://localhost', 'http://localhost/foo:1'],
+            ['/bar:1', 'http://localhost', 'http://localhost/bar:1'],
+            ['foo/bar:1', 'http://localhost', 'http://localhost/foo/bar:1'],
         ];
     }
 }
diff --git a/UriResolver.php b/UriResolver.php
index d3b0c83..c81dc7b 100644
--- a/UriResolver.php
+++ b/UriResolver.php
@@ -33,7 +33,7 @@ public static function resolve(string $uri, ?string $baseUri): string
         $uri = trim($uri);
 
         // absolute URL?
-        if (null !== parse_url($uri, \PHP_URL_SCHEME)) {
+        if (\is_string(parse_url($uri, \PHP_URL_SCHEME))) {
             return $uri;
         }