diff --git a/src/Skybrud.Essentials.AspNetCore/QueryStringExtensions.cs b/src/Skybrud.Essentials.AspNetCore/QueryStringExtensions.cs
index d82bbcd..d4e187d 100644
--- a/src/Skybrud.Essentials.AspNetCore/QueryStringExtensions.cs
+++ b/src/Skybrud.Essentials.AspNetCore/QueryStringExtensions.cs
@@ -219,7 +219,7 @@ public static bool GetBoolean(this IQueryCollection query, string key, bool fall
         /// </summary>
         /// <param name="query">The query string to be encoded.</param>
         /// <returns>The URL encoded version of the query string.</returns>
-        public static string ToUrlEncodedString(IQueryCollection query) {
+        public static string ToUrlEncodedString(this IQueryCollection query) {
 
             StringBuilder sb = new();