diff --git a/src/Program.cs b/src/Program.cs
index 548109c..1627f52 100644
--- a/src/Program.cs
+++ b/src/Program.cs
@@ -36,7 +36,7 @@ namespace Palettizer2
 	        var writer = new StbImageWriteSharp.ImageWriter();
 
 	        // add all sprite colors to palette
-	        foreach (var imageFile in directory.EnumerateFiles("*.png"))
+	        foreach (var imageFile in directory.EnumerateFiles("*.png", SearchOption.AllDirectories))
 	        {
 		        System.Console.WriteLine(imageFile.FullName);