diff --git a/codegen/build.rs b/codegen/build.rs
index f95b6bb5..45b190ba 100644
--- a/codegen/build.rs
+++ b/codegen/build.rs
@@ -8,8 +8,8 @@ use ansi_term::Colour::{Red, Yellow, Blue, White};
 use version_check::{is_nightly, is_min_version, is_min_date};
 
 // Specifies the minimum nightly version needed to compile Rocket's codegen.
-const MIN_DATE: &'static str = "2017-03-22";
-const MIN_VERSION: &'static str = "1.17.0-nightly";
+const MIN_DATE: &'static str = "2017-03-30";
+const MIN_VERSION: &'static str = "1.18.0-nightly";
 
 // Convenience macro for writing to stderr.
 macro_rules! printerr {
diff --git a/codegen/src/utils/mod.rs b/codegen/src/utils/mod.rs
index 41664c53..cb9960d6 100644
--- a/codegen/src/utils/mod.rs
+++ b/codegen/src/utils/mod.rs
@@ -17,7 +17,7 @@ use syntax::parse::token::Token;
 use syntax::tokenstream::TokenTree;
 use syntax::ast::{Item, Expr};
 use syntax::ext::base::{Annotatable, ExtCtxt};
-use syntax::codemap::{spanned, Span, Spanned, DUMMY_SP};
+use syntax::codemap::{Span, Spanned, DUMMY_SP};
 use syntax::ext::quote::rt::ToTokens;
 use syntax::print::pprust::item_to_string;
 use syntax::ptr::P;
@@ -26,7 +26,7 @@ use syntax::ast::{Attribute, Lifetime, LifetimeDef, Ty};
 use syntax::attr::HasAttrs;
 
 pub fn span<T>(t: T, span: Span) -> Spanned<T> {
-    spanned(span.lo, span.hi, t)
+    Spanned { node: t, span: span }
 }
 
 pub fn sep_by_tok<T>(ecx: &ExtCtxt, things: &[T], token: Token) -> Vec<TokenTree>