diff --git a/Cargo.lock b/Cargo.lock
index ea3bb71..0d45d9b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -252,7 +252,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.6"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -271,7 +271,7 @@ name = "quote"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.24 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -330,7 +330,7 @@ dependencies = [
 name = "rate-macros"
 version = "0.3.0"
 dependencies = [
- "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -410,7 +410,7 @@ name = "serde_derive"
 version = "1.0.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -455,7 +455,7 @@ name = "syn"
 version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -614,7 +614,7 @@ dependencies = [
 "checksum miniz_oxide 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6f3f74f726ae935c3f514300cc6773a0c9492abc5e972d42ba0c0ebb88757625"
 "checksum num_cpus 1.11.1 (registry+https://github.com/rust-lang/crates.io-index)" = "76dac5ed2a876980778b8b85f75a71b6cbf0db0b1232ee12f826bccb00d09d72"
 "checksum pkg-config 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)" = "05da548ad6865900e60eaba7f589cc0783590a92e940c26953ff81ddbab2d677"
-"checksum proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "9c9e470a8dc4aeae2dee2f335e8f533e2d4b347e1434e5671afc49b054592f27"
+"checksum proc-macro2 1.0.24 (registry+https://github.com/rust-lang/crates.io-index)" = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
 "checksum pulldown-cmark 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "eef52fac62d0ea7b9b4dc7da092aa64ea7ec3d90af6679422d3d7e0e14b6ee15"
 "checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
 "checksum rand 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "552840b97013b1a26992c11eac34bdd778e464601a4c2054b5f0bff7c6761293"