diff --git a/lib/mix/tasks/tableau.build.ex b/lib/mix/tasks/tableau.build.ex
index a7f1511..cffa01b 100644
--- a/lib/mix/tasks/tableau.build.ex
+++ b/lib/mix/tasks/tableau.build.ex
@@ -65,7 +65,7 @@ defmodule Mix.Tasks.Tableau.Build do
 
     token = mods |> extensions_for(:pre_write) |> run_extensions(:pre_write, token)
 
-    for %{body: body, permalink: permalink} <- pages do
+    for %{body: body, permalink: permalink} <- token.site[:pages] do
       file_path = build_file_path(out, permalink)
       dir = Path.dirname(file_path)
 
diff --git a/test/mix/tasks/tableau.build_test.exs b/test/mix/tasks/tableau.build_test.exs
index 2be65b2..92e9483 100644
--- a/test/mix/tasks/tableau.build_test.exs
+++ b/test/mix/tasks/tableau.build_test.exs
@@ -25,7 +25,9 @@ defmodule Mix.Tasks.Tableau.FooExtension do
   def pre_write(token) do
     pages =
       for page <- token.site.pages do
-        Map.put(page, :foo, "bar")
+        page
+        |> Map.put(:foo, "bar")
+        |> Map.put(:body, page.body <> "<!-- foo: bar -->\n")
       end
 
     {:ok, put_in(token.site.pages, pages)}
@@ -189,10 +191,16 @@ defmodule Mix.Tasks.Tableau.BuildTest do
 
     assert log =~ "FailExtension failed to run"
 
-    assert File.exists?(Path.join(out, "/index.html"))
-    assert File.exists?(Path.join(out, "/about/index.html"))
-    assert File.exists?(Path.join(out, "/a-bing-bong-blog-post/index.html"))
-    assert File.exists?(Path.join(out, "/some/deeply/nested/page/my-page/index.html"))
+    for file <- [
+          "/index.html",
+          "/about/index.html",
+          "/a-bing-bong-blog-post/index.html",
+          "/some/deeply/nested/page/my-page/index.html"
+        ] do
+      path = Path.join(out, file)
+      assert File.exists?(path)
+      assert path |> File.read!() |> String.ends_with?("<!-- foo: bar -->\n")
+    end
   end
 
   @tag :tmp_dir