diff --git a/lib/cooked_post_processor.rb b/lib/cooked_post_processor.rb
index 233f299d11a..262b4f0a902 100644
--- a/lib/cooked_post_processor.rb
+++ b/lib/cooked_post_processor.rb
@@ -107,13 +107,18 @@ class CookedPostProcessor
   end
 
   def get_size(url)
+    return @size_cache[url] if @size_cache.has_key?(url)
+
     absolute_url = url
     absolute_url = Discourse.base_url_no_prefix + absolute_url if absolute_url =~ /^\/[^\/]/
     # FastImage fails when there's no scheme
     absolute_url = SiteSetting.scheme + ":" + absolute_url if absolute_url.start_with?("//")
+
     return unless is_valid_image_url?(absolute_url)
+
     # we can *always* crawl our own images
     return unless SiteSetting.crawl_images? || Discourse.store.has_been_uploaded?(url)
+
     @size_cache[url] ||= FastImage.size(absolute_url)
   rescue Zlib::BufError # FastImage.size raises BufError for some gifs
   end
@@ -131,6 +136,12 @@ class CookedPostProcessor
     width, height = img["width"].to_i, img["height"].to_i
     original_width, original_height = get_size(src)
 
+    # can't reach the image...
+    if original_width.nil? || original_height.nil?
+      Rails.logger.error "Can't reach '#{src}' to get its dimension."
+      return
+    end
+
     return if original_width.to_i <= width && original_height.to_i <= height
     return if original_width.to_i <= SiteSetting.max_image_width && original_height.to_i <= SiteSetting.max_image_height