diff --git a/Cargo.lock b/Cargo.lock
index 5bc14c29..8cd85ee2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -539,7 +539,7 @@ dependencies = [
  "indexmap 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-util 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -632,7 +632,7 @@ dependencies = [
  "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "tower-service 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "want 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -649,7 +649,7 @@ dependencies = [
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustls 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustls-native-certs 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-rustls 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "webpki 0.21.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -662,7 +662,7 @@ dependencies = [
  "bytes 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.13.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "native-tls 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-tls 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1230,7 +1230,7 @@ dependencies = [
  "serde 1.0.110 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_urlencoded 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-tls 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasm-bindgen 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1278,7 +1278,7 @@ dependencies = [
  "serde 1.0.110 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.53 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha2 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "xml-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1297,7 +1297,7 @@ dependencies = [
  "serde 1.0.110 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.53 (registry+https://github.com/rust-lang/crates.io-index)",
  "shlex 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "zeroize 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1322,7 +1322,7 @@ dependencies = [
  "serde 1.0.110 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha2 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1783,7 +1783,7 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "0.2.13"
+version = "0.2.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1820,7 +1820,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "futures-core 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustls 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "webpki 0.21.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1830,7 +1830,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "native-tls 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1843,7 +1843,7 @@ dependencies = [
  "futures-sink 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project-lite 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1903,7 +1903,7 @@ dependencies = [
  "snafu 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "tough 0.5.0",
  "url 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "walkdir 2.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2359,7 +2359,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum time 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)" = "6329a7835505d46f5f3a9a2c237f8d6bf5ca6f0015decb3698ba57fcdbb609ba"
 "checksum time-macros 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9ae9b6e9f095bc105e183e3cd493d72579be3181ad4004fceb01adbe9eecab2d"
 "checksum time-macros-impl 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e987cfe0537f575b5fc99909de6185f6c19c3ad8889e2275e686a873d0869ba1"
-"checksum tokio 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)" = "0fa5e81d6bc4e67fe889d5783bd2a128ab2e0cfa487e0be16b6a8d177b101616"
+"checksum tokio 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)" = "05c1d570eb1a36f0345a5ce9c6c6e665b70b73d11236912c0b477616aeec47b1"
 "checksum tokio-macros 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "f0c3acc6aa564495a0f2e1d59fab677cd7f81a19994cfc7f3ad0e64301560389"
 "checksum tokio-rustls 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4adb8b3e5f86b707f1b54e7c15b6de52617a823608ccda98a15d3a24222f265a"
 "checksum tokio-tls 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7bde02a3a5291395f59b06ec6945a3077602fac2b07eeeaf0dee2122f3619828"
diff --git a/tuftool/Cargo.toml b/tuftool/Cargo.toml
index 2bf069c7..55bf4d35 100644
--- a/tuftool/Cargo.toml
+++ b/tuftool/Cargo.toml
@@ -34,7 +34,7 @@ tempfile = "3.1.0"
 url = "2.1.0"
 walkdir = "2.2.9"
 tough = { version = "0.5.0", path = "../tough", features = ["http"] }
-tokio = "0.2.13"
+tokio = "0.2.20"
 
 [dev-dependencies]
 assert_cmd = "1.0"