diff --git a/SMILEBASIC/project.d b/SMILEBASIC/project.d
index 7af7e01..54f2037 100644
--- a/SMILEBASIC/project.d
+++ b/SMILEBASIC/project.d
@@ -67,7 +67,7 @@ r"ファイルを書き込みます。
     }
     static bool isValidFileName(C)(C[] filename) if(isSomeChar!(C))
     {
-        if(filename.length > 12)
+        if(filename.length > 14)
         {
             return false;
         }