diff --git a/src/rustdoc/gen.rs b/src/rustdoc/gen.rs
index e53bb15a9c72..b58287d2ce84 100644
--- a/src/rustdoc/gen.rs
+++ b/src/rustdoc/gen.rs
@@ -1,3 +1,8 @@
+type rustdoc = {
+    ps: pprust::ps,
+    w: io::writer
+};
+
 #[doc(
   brief = "Generate a crate document header.",
   args(rd = "Rustdoc context",