diff --git a/src/libsyntax/ext/auto_encode.rs b/src/libsyntax/ext/auto_encode.rs
index 457c3ce5110..6995155af18 100644
--- a/src/libsyntax/ext/auto_encode.rs
+++ b/src/libsyntax/ext/auto_encode.rs
@@ -1023,6 +1023,8 @@ fn mk_enum_deser_variant_nary(
                 cx.expr_path(span, ~[
                     cx.ident_of(~"std"),
                     cx.ident_of(~"serialize"),
+                    cx.ident_of(~"traits"),
+                    cx.ident_of(~"Decodable"),
                     cx.ident_of(~"decode"),
                 ]),
                 ~[cx.expr_var(span, ~"__d")]