@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [nightly, beta, stable, 1.42.0, 1.31.0]
+        rust: [nightly, beta, stable, 1.45.0, 1.42.0, 1.31.0]
     steps:
       - uses: actions/checkout@v2
       - uses: dtolnay/rust-toolchain@master
 
@@ -3,5 +3,5 @@ use proc_macro_hack::proc_macro_hack;
 /// Add one to an expression.
 ///
 /// (Documentation goes here on the re-export, not in the other crate.)
-#[proc_macro_hack]
+#[proc_macro_hack(only_hack_old_rustc)]
 pub use demo_hack_impl::add_one;