Disable resizing of gif when uploaded

Animated gifs are getting more popular on the web (again) and currently there is no good tool for resizing animated gifs.

So I want to disable resizing/generation of image sizes for the gif mimetype and just save the original gif.

Someone that can help me out with this? Which filter to use will be a good start.

image_make_intermediate_size was not the hook I was looking for, but intermediate_image_sizes_advanced.

Here is a working code:

function disable_upload_sizes( $sizes, $metadata ) {

    // Get filetype data.
    $filetype = wp_check_filetype($metadata['file']);

    // Check if is gif. 
    if($filetype['type'] == 'image/gif') {
        // Unset sizes if file is gif.
        $sizes = array();
    }

    // Return sizes you want to create from image (None if image is gif.)
    return $sizes;
}   
add_filter('intermediate_image_sizes_advanced', 'disable_upload_sizes', 10, 2);