diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1aa170b..10cd279 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,7 +22,7 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml', '.github/workflows/*.yml') }}
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml', '.github/workflows/*.yml', 'rust-toolchain') }}
 
       - name: Install Python
         uses: actions/setup-python@v4
@@ -31,7 +31,6 @@ jobs:
 
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
           components: rustfmt, clippy
 
       - name: Install cargo-deny
diff --git a/README.md b/README.md
index 42e2ccc..a0acfce 100644
--- a/README.md
+++ b/README.md
@@ -17,8 +17,6 @@ Reconstruction probability after receiving K + h packets = 1 - 1/256^(h + 1). Wh
 original message, and h is the number of additional packets received.
 See "RaptorQ Technical Overview" by Qualcomm
 
-This crate requires Rust 1.46 or newer.
-
 ### Examples
 See the `examples/` directory for usage.
 
diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 0000000..5b6cd6b
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+1.65