diff --git a/Cargo.lock b/Cargo.lock
index 35fd88e..7bd24c7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
@@ -20,12 +22,24 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "clap"
 version = "2.33.3"
@@ -41,6 +55,56 @@ dependencies = [
  "vec_map",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6455c0ca19f0d2fbf751b908d5c55c1f5cbc65e03c4225427254b46890bdde1e"
+dependencies = [
+ "cfg-if",
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c00d6d2ea26e8b151d99093005cb442fb9a37aeaca582a03ec70946f49ab5ed9"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+ "lazy_static",
+ "memoffset",
+ "scopeguard",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5e5bed1f1c269533fa816a0a5492b3545209a205ca1a54842be180eb63a16a6"
+dependencies = [
+ "cfg-if",
+ "lazy_static",
+]
+
+[[package]]
+name = "either"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
+
 [[package]]
 name = "heck"
 version = "0.3.2"
@@ -63,6 +127,7 @@ dependencies = [
 name = "indivisible"
 version = "2.0.0"
 dependencies = [
+ "rayon",
  "structopt",
 ]
 
@@ -78,6 +143,25 @@ version = "0.2.87"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "265d751d31d6780a3f956bb5b8022feba2d94eeee5a84ba64f4212eedca42213"
 
+[[package]]
+name = "memoffset"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aa361d4faea93603064a027415f07bd8e1d5c88c9fbf68bf56a285428fd79ce"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "num_cpus"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19e64526ebdee182341572e50e9ad03965aa510cd94427a4549448f285e957a1"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -120,6 +204,37 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c06aca804d41dbc8ba42dfd964f0d01334eceb64314b9ecf7c5fad5188a06d90"
+dependencies = [
+ "autocfg",
+ "crossbeam-deque",
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d78120e2c850279833f1dd3582f730c4ab53ed95aeaaaa862a2a5c71b1656d8e"
+dependencies = [
+ "crossbeam-channel",
+ "crossbeam-deque",
+ "crossbeam-utils",
+ "lazy_static",
+ "num_cpus",
+]
+
+[[package]]
+name = "scopeguard"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
+
 [[package]]
 name = "strsim"
 version = "0.8.0"
diff --git a/Cargo.toml b/Cargo.toml
index f452260..5fff3e4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,3 +12,4 @@ keywords = ["primes", "math"]
 
 [dependencies]
 structopt = "0.3.13"
+rayon = "1.5"