diff --git a/run-pre-commit/README.md b/run-pre-commit/README.md
index 3b61c8d..0614777 100644
--- a/run-pre-commit/README.md
+++ b/run-pre-commit/README.md
@@ -41,6 +41,7 @@ jobs:
 - `pre-commit-version` (defaults to `4.2.0`)
 - `rust` (eg: `1.80.1`. Disabled if not specified)
 - `rust-components` (defaults to `rustfmt,clippy`)
+- `rustup-version` (defaults to `1.28.1`)
 - `hadolint` (eg: `v2.12.0`. Disabled if not specified)
 - `nix` (eg: `2.25.2`. Disabled if not specified)
 - `nix-github-token` (eg: `secrets.GITHUB_TOKEN`. Required when `nix` is set)
diff --git a/run-pre-commit/action.yml b/run-pre-commit/action.yml
index f3e43f1..30421b0 100644
--- a/run-pre-commit/action.yml
+++ b/run-pre-commit/action.yml
@@ -18,6 +18,9 @@ inputs:
       Override which Rust components are installed. Only takes effect when Rust
       is installed.
     default: rustfmt,clippy
+  rustup-version:
+    description: Rustup version used when setting up the Rust toolchain(s)
+    default: 1.28.1
   hadolint:
     description: Whether to install hadolint (and which version to use)
   nix:
@@ -74,7 +77,7 @@ runs:
       uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
       with:
         path: ~/.rustup/toolchains
-        key: rust-toolchains-${{ inputs.rust }}-components-${{ env.RUST_COMPONENTS }}
+        key: rust-toolchains-${{ inputs.rust }}-components-${{ env.RUST_COMPONENTS }}-rustup-${{ inputs.rustup-version }}
 
     - name: Setup Rust Toolchain
       uses: dtolnay/rust-toolchain@56f84321dbccf38fb67ce29ab63e4754056677e0
@@ -82,6 +85,7 @@ runs:
       with:
         toolchain: ${{ inputs.rust }}
         components: ${{ inputs.rust-components }}
+        rustup-version: ${{ inputs.rustup-version }}
 
     - name: Install Hadolint
       if: ${{ inputs.hadolint }}