diff --git a/src/Uri.php b/src/Uri.php
index f5edf41..9828a4c 100644
--- a/src/Uri.php
+++ b/src/Uri.php
@@ -35,7 +35,7 @@ class Uri
 
     protected const PATH_REGEX = '`^(?:(?:%[a-f0-9]{2})+|[a-z0-9-._~!$&\'()*+,;=:@/]+)*$`i';
 
-    protected const QUERY_OR_FRAGMENT_REGEX = '`^(?:(?:%[a-f0-9]{2})+|[a-z0-9-._~!$&\'"()\[\]*+,;=:@?/%]+)*$`i';
+    protected const QUERY_OR_FRAGMENT_REGEX = '`^(?:(?:%[a-f0-9]{2})+|[a-z0-9-._~!$&\'"()\[\]*+,;=:@?/%{}]+)*$`i';
 
     protected array $components;
 
diff --git a/tests/UriMergeTest.php b/tests/UriMergeTest.php
index 7f331a0..036a80e 100644
--- a/tests/UriMergeTest.php
+++ b/tests/UriMergeTest.php
@@ -45,6 +45,7 @@ public function uriProvider()
             ["//g", "http://g"],
             ["?y", "http://a/b/c/d;p?y"],
             ["g?y", "http://a/b/c/g?y"],
+            ["g?y={y}", "http://a/b/c/g?y={y}"],
             ["#s", "http://a/b/c/d;p?q#s"],
             ["g#s", "http://a/b/c/g#s"],
             ["g?y#s", "http://a/b/c/g?y#s"],