diff --git a/src/librustc_driver/pretty.rs b/src/librustc_driver/pretty.rs
index 3382b70b35b2..0de5b700b4fa 100644
--- a/src/librustc_driver/pretty.rs
+++ b/src/librustc_driver/pretty.rs
@@ -101,9 +101,9 @@ pub fn parse_pretty(sess: &Session,
             if extended {
                 sess.fatal(&format!("argument to `unpretty` must be one of `normal`, \
                                      `expanded`, `identified`, `expanded,identified`, \
-                                     `everybody_loops`, `hir`, `hir,identified`, \
-                                     `hir,typed`, `hir-tree`, `mir` or `mir-cfg`; \
-                                     got {}",
+                                     `expanded,hygiene`, `everybody_loops`, \
+                                     `hir`, `hir,identified`, `hir,typed`, `hir-tree`, \
+                                     `mir` or `mir-cfg`; got {}",
                                     name));
             } else {
                 sess.fatal(&format!("argument to `pretty` must be one of `normal`, `expanded`, \