diff --git a/sigal/templates/sigal.conf.py b/sigal/templates/sigal.conf.py
index 5f61d9d..480fbad 100644
--- a/sigal/templates/sigal.conf.py
+++ b/sigal/templates/sigal.conf.py
@@ -41,7 +41,7 @@ theme = 'galleria'
 img_size = (800, 600)
 
 # Output format of images (default: None, i.e. use input format)
-img_format = "JPEG"
+# img_format = "JPEG"
 
 # Show a map of the images where possible?
 # This option only has an effect on the galleria theme for the while.