diff --git a/README.markdown b/README.markdown
index 6829fe2..f806efa 100644
--- a/README.markdown
+++ b/README.markdown
@@ -116,7 +116,7 @@ A more advanced example with JSON would be:
 }
 ```
 
-Because there's no `chapter_selector` here, leech will keep on looking for a link which it can find with `next_selector` and following that link. *Yes*, it would be easy to make this an endless loop; don't do that. We also see more advanced metadata acquisition here, with `content_title_selector` and `content_text_selector` being used to find specific elements from within the content.
+Because there's no `chapter_selector` here, leech will keep on looking for a link which it can find with `next_selector` and following that link. We also see more advanced metadata acquisition here, with `content_title_selector` and `content_text_selector` being used to find specific elements from within the content.
 
 If multiple matches for `content_selector` are found, leech will assume multiple chapters are present on one page, and will handle that. If you find a story that you want on a site which has all the chapters in the right order and next-page links, this is a notably efficient way to download it. See `examples/dungeonkeeperami.json` for this being used.
 
diff --git a/sites/arbitrary.py b/sites/arbitrary.py
index 7701a77..9a6da32 100644
--- a/sites/arbitrary.py
+++ b/sites/arbitrary.py
@@ -75,8 +75,11 @@ class Arbitrary(Site):
                 for chapter in self._chapter(chapter_url, definition, title=chapter_link.string):
                     story.add(chapter)
         else:
+            # set of already processed urls. Stored to detect loops.
+            found_content_urls = set()
             content_url = definition.url
-            while content_url:
+            while content_url and content_url not in found_content_urls:
+                found_content_urls.add(content_url)
                 for chapter in self._chapter(content_url, definition):
                     story.add(chapter)
                 if definition.next_selector: