diff --git a/boards/thumbs.py b/boards/thumbs.py
--- a/boards/thumbs.py
+++ b/boards/thumbs.py
@@ -26,10 +26,6 @@ def generate_thumb(img, thumb_size, form
     img.seek(0) # see http://code.djangoproject.com/ticket/8222 for details
     image = Image.open(img)
     
-    # Convert to RGB if necessary
-    if image.mode not in ('L', 'RGB'):
-        image = image.convert('RGB')
-        
     # get size
     thumb_w, thumb_h = thumb_size
     # If you want to generate a square thumbnail