diff --git a/src/lib.rs b/src/lib.rs
index b4757c54..897768c5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -86,6 +86,7 @@ extern crate log;
 pub mod book;
 pub mod config;
 mod parse;
+mod preprocess;
 pub mod renderer;
 pub mod theme;
 pub mod utils;
diff --git a/src/renderer/html_handlebars/helpers/playpen.rs b/src/preprocess/links.rs
similarity index 100%
rename from src/renderer/html_handlebars/helpers/playpen.rs
rename to src/preprocess/links.rs
diff --git a/src/preprocess/mod.rs b/src/preprocess/mod.rs
new file mode 100644
index 00000000..19b2f4d4
--- /dev/null
+++ b/src/preprocess/mod.rs
@@ -0,0 +1 @@
+pub mod links;
diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index b1ba47ca..321fcc87 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -1,4 +1,5 @@
 use renderer::html_handlebars::helpers;
+use preprocess;
 use renderer::Renderer;
 use book::MDBook;
 use book::bookitem::{BookItem, Chapter};
@@ -46,7 +47,7 @@ impl HtmlHandlebars {
 
                     // Parse for playpen links
                     if let Some(p) = path.parent() {
-                        content = helpers::playpen::render_playpen(&content, p);
+                        content = preprocess::links::render_playpen(&content, p);
                     }
 
                     content = utils::render_markdown(&content, ctx.book.get_curly_quotes());
diff --git a/src/renderer/html_handlebars/helpers/mod.rs b/src/renderer/html_handlebars/helpers/mod.rs
index 2fc287c2..62fc6149 100644
--- a/src/renderer/html_handlebars/helpers/mod.rs
+++ b/src/renderer/html_handlebars/helpers/mod.rs
@@ -1,3 +1,2 @@
 pub mod navigation;
 pub mod toc;
-pub mod playpen;