diff --git a/Cargo.lock b/Cargo.lock
index bb3d281..b237e6b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2825,9 +2825,9 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "tokio"
-version = "1.39.3"
+version = "1.40.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9babc99b9923bfa4804bd74722ff02c0381021eafa4db9949217e3be8e84fff5"
+checksum = "e2b070231665d27ad9ec9b8df639893f46727666c6767db40317fbe920a5d998"
 dependencies = [
  "backtrace",
  "bytes",
diff --git a/mdbook-slide-evaluator/Cargo.toml b/mdbook-slide-evaluator/Cargo.toml
index 827f027..8ca3fc7 100644
--- a/mdbook-slide-evaluator/Cargo.toml
+++ b/mdbook-slide-evaluator/Cargo.toml
@@ -17,6 +17,6 @@ log = "0.4.22"
 pretty_env_logger = "0.5.0"
 serde = { version = "1.0.209", features = ["derive"] }
 strum = { version = "0.26.3", features = ["derive"] }
-tokio = { version = "1.38.1", features = ["full"] }
+tokio = { version = "1.40.0", features = ["full"] }
 tokio-util = "0.7.11"
 url = "2.5.2"
diff --git a/src/concurrency/async-exercises/chat-async/Cargo.toml b/src/concurrency/async-exercises/chat-async/Cargo.toml
index a42a63b..ad4a431 100644
--- a/src/concurrency/async-exercises/chat-async/Cargo.toml
+++ b/src/concurrency/async-exercises/chat-async/Cargo.toml
@@ -6,5 +6,5 @@ edition = "2021"
 [dependencies]
 futures-util = { version = "0.3.30", features = ["sink"] }
 http = "1.1.0"
-tokio = { version = "1.39.3", features = ["full"] }
+tokio = { version = "1.40.0", features = ["full"] }
 tokio-websockets = { version = "0.9.0", features = ["client", "fastrand", "server", "sha1_smol"] }