diff --git a/WGneu/App.xaml.cs b/WGneu/App.xaml.cs
index 72520b5..36e8165 100644
--- a/WGneu/App.xaml.cs
+++ b/WGneu/App.xaml.cs
@@ -6,6 +6,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
+using System.IO;
 
 namespace WGneu {
     public partial class App : Application {
@@ -15,6 +16,7 @@ namespace WGneu {
 
         public App() : base() {
             System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
+            Directory.CreateDirectory(Path.Combine(Path.GetTempPath(), "Kelwin"));
             MainDispatcher = Dispatcher;
         }
 
diff --git a/WGneu/Documents/Document.cshtml.cs b/WGneu/Documents/Document.cshtml.cs
index eacb2d6..8863d38 100644
--- a/WGneu/Documents/Document.cshtml.cs
+++ b/WGneu/Documents/Document.cshtml.cs
@@ -50,8 +50,8 @@ namespace WGneu.Documents {
         }
 
         public async Task Generate() {
-            var pdf = new Utils.TemporaryFile(".pdf");
-            using (var tmpHtml = new Utils.TemporaryFile(".html")) {
+            var pdf = new Utils.TemporaryFile("pdf");
+            using (var tmpHtml = new Utils.TemporaryFile("html")) {
                 await File.WriteAllTextAsync(tmpHtml.FilePath, await Render());
                 await Pdf.Convert(tmpHtml.FilePath, pdf.FilePath);
             }
diff --git a/WGneu/Utils.cs b/WGneu/Utils.cs
index b214b23..78ed22a 100644
--- a/WGneu/Utils.cs
+++ b/WGneu/Utils.cs
@@ -60,12 +60,12 @@ namespace WGneu {
             private int Usages = 0;
             public string FilePath { get; private set; }
 
-            public TemporaryFile() : this("") {}
+            public TemporaryFile() : this(null) {}
 
-            public TemporaryFile(string ext) : this(Path.GetTempPath(), ext) {}
+            public TemporaryFile(string? ext) : this(Path.Combine(Path.GetTempPath(), "Kelwin"), ext) {}
 
-            public TemporaryFile(string dir, string ext) {
-                FilePath = Path.Combine(dir, Path.GetRandomFileName() + ext);
+            public TemporaryFile(string dir, string? ext) {
+                FilePath = Path.Combine(dir, Path.GetRandomFileName().Replace(".", "") + (ext != null ? $".{ext}" : ""));
                 Usages++;
                 Create();
             }