diff --git a/Cargo.lock b/Cargo.lock
index 13984c7..51f5025 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,7 +17,7 @@ dependencies = [
  "mustache 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "numerals 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pulldown-cmark 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rayon 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -659,9 +659,10 @@ dependencies = [
 
 [[package]]
 name = "rayon"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
+ "either 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon-core 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1145,7 +1146,7 @@ dependencies = [
 "checksum pulldown-cmark 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a656fdb8b6848f896df5e478a0eb9083681663e37dcb77dd16981ff65329fe8b"
 "checksum quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e920b65c65f10b2ae65c831a81a073a89edd28c7cce89475bff467ab4167a"
 "checksum rand 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)" = "6475140dfd8655aeb72e1fd4b7a1cc1c202be65d71669476e392fe62532b9edd"
-"checksum rayon 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b614fe08b6665cb9a231d07ac1364b0ef3cb3698f1239ee0c4c3a88a524f54c8"
+"checksum rayon 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ed02d09394c94ffbdfdc755ad62a132e94c3224a8354e78a1200ced34df12edf"
 "checksum rayon-core 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e64b609139d83da75902f88fd6c01820046840a18471e4dfcd5ac7c0f46bea53"
 "checksum redox_syscall 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)" = "8dde11f18c108289bef24469638a04dce49da56084f2d50618b226e47eb04509"
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
diff --git a/Cargo.toml b/Cargo.toml
index 3e1f7b6..5f91736 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -50,7 +50,7 @@ mustache = "0.8"
 uuid = { version = "0.5", features = ["v4"] }
 walkdir = "2"
 rustc-serialize = "0.3"
-rayon = "0.8"
+rayon = "0.9"
 crowbook-text-processing = "^0.2.6"
 lazy_static = "0.2.1"
 crowbook-intl-runtime = "0.1"