diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a1c4af2..6ff5fdc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,7 +10,7 @@ jobs:
       matrix:
         rust:
           - stable
-          - 1.55.0
+          - 1.56.0
     steps:
       - name: Checkout sources
         uses: actions/checkout@v2
@@ -39,7 +39,7 @@ jobs:
       matrix:
         rust:
           - stable
-          - 1.55.0
+          - 1.56.0
     steps:
       - name: Checkout sources
         uses: actions/checkout@v2
diff --git a/Cargo.toml b/Cargo.toml
index 14adbc5..6eca0d0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "onetun"
 version = "0.3.1"
-edition = "2018"
+edition = "2021"
 license = "MIT"
 description = "A cross-platform, user-space WireGuard port-forwarder that requires no system network configurations."
 authors = ["Aram Peres <aram.peres@gmail.com>"]
diff --git a/Dockerfile b/Dockerfile
index 9edc22a..475bfc9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,11 @@
-FROM rust:1.55 as cargo-build
+FROM rust:1.56 as cargo-build
 
 WORKDIR /usr/src/onetun
 COPY Cargo.toml Cargo.toml
 
 # Placeholder to download dependencies and cache them using layering
 RUN mkdir src/
+RUN touch src/lib.rs
 RUN echo "fn main() {println!(\"if you see this, the build broke\")}" > src/main.rs
 RUN cargo build --release
 RUN rm -f target/x86_64-unknown-linux-musl/release/deps/myapp*
diff --git a/README.md b/README.md
index 9760ca6..1b06356 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ For example,
 
 ## Download
 
-onetun is available to install from [crates.io](https://crates.io/crates/onetun) with Rust ≥1.55:
+onetun is available to install from [crates.io](https://crates.io/crates/onetun) with Rust ≥1.56:
 
 ```shell
 $ cargo install onetun
@@ -37,7 +37,7 @@ $ docker run --rm --name onetun --user 1000 -p 8080:8080 aramperes/onetun \
     0.0.0.0:8080:192.168.4.2:8080 [...options...]
 ```
 
-You can also build onetun locally, using Rust ≥1.55:
+You can also build onetun locally, using Rust ≥1.56:
 
 ```shell
 $ git clone https://github.com/aramperes/onetun && cd onetun