diff --git a/filter.hs b/filter.hs
index 5116c38..e8ea307 100755
--- a/filter.hs
+++ b/filter.hs
@@ -5,7 +5,9 @@ import qualified Data.Text.IO as TIO
 import qualified Data.Text as T
 
 file2Block :: FilePath -> IO [Block]
-
+file2Block f = do
+  contents <- TIO.readFile f
+  return [Plain [Str contents]]
 
 doInclude :: Block -> IO Block
 doInclude cb@(Div (id, classes, namevals) contents) =
diff --git a/output.html b/output.html
index 9487283..d9560f9 100644
--- a/output.html
+++ b/output.html
@@ -1,6 +1,28 @@
 <p>Here’s the pandoc README:</p>
+<div class="sourceCode" id="cb1" data-include="filter.hs"><pre
+class="sourceCode haskell"><code class="sourceCode haskell"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="dt">Foo</span><span class="ot">::</span> <span class="dt">Div</span> <span class="ot">-&gt;</span> <span class="dt">Div</span></span></code></pre></div>
 <div data-include="filter.hs">
+#!/usr/bin/env runhaskell
+-- filter.hs
+import Text.Pandoc.JSON
+import qualified Data.Text.IO as TIO
+import qualified Data.Text as T
 
+file2Block :: FilePath -&gt; IO [Block]
+file2Block f = do
+  contents &lt;- TIO.readFile f
+  return [Plain [Str contents]]
+
+doInclude :: Block -&gt; IO Block
+doInclude cb@(Div (id, classes, namevals) contents) =
+  case lookup (T.pack "include") namevals of
+       Just f     -&gt; Div (id, classes, namevals) &lt;$&gt;
+                      file2Block (T.unpack f)
+       Nothing    -&gt; return cb
+doInclude x = return x
+
+main :: IO ()
+main = toJSONFilter doInclude
 </div>
 <div class="Theorem">
 <p>test thm1</p>