diff --git a/Cargo.lock b/Cargo.lock
index 19dadaa1400..ad4af76f4b3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2365,6 +2365,7 @@ dependencies = [
  "rustc_data_structures 0.0.0",
  "rustc_errors 0.0.0",
  "rustc_fs_util 0.0.0",
+ "rustc_macros 0.1.0",
  "rustc_target 0.0.0",
  "scoped-tls 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serialize 0.0.0",
@@ -2817,6 +2818,16 @@ dependencies = [
  "core 0.0.0",
 ]
 
+[[package]]
+name = "rustc_macros"
+version = "0.1.0"
+dependencies = [
+ "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rustc_metadata"
 version = "0.0.0"