diff --git a/dnSpy.Theme.Installer/Program.cs b/dnSpy.Theme.Installer/Program.cs
index 832d1b6..c36985d 100644
--- a/dnSpy.Theme.Installer/Program.cs
+++ b/dnSpy.Theme.Installer/Program.cs
@@ -34,7 +34,7 @@ private static int Main(string[] args)
         string? flagName = null;
         foreach (var arg in args)
         {
-            if (arg.StartsWith('-'))
+            if (arg.StartsWith('-') && arg.Length > 1)
             {
                 //Flag
                 if (flagName != null)