diff --git a/CardSharp/StringExtensions.cs b/CardSharp/StringExtensions.cs
index 310adf7..16a4fd3 100644
--- a/CardSharp/StringExtensions.cs
+++ b/CardSharp/StringExtensions.cs
@@ -14,7 +14,7 @@ public static string AddNewLine(this string source)
 
         public static bool IsValidCardString(this string source)
         {
-            return Regex.IsMatch(source, "([2-9]|10|A|王|鬼)*");
+            return Regex.IsMatch(source, "([2-9]|10|A|王|鬼).*");
         }
 
         public static IEnumerable<Card> ToCards(this string source)