diff --git a/.github/workflows/msrv.yml b/.github/workflows/msrv.yml
new file mode 100644
index 0000000..5fd392e
--- /dev/null
+++ b/.github/workflows/msrv.yml
@@ -0,0 +1,20 @@
+name: Min Supported Rust Version
+
+on:
+  push:
+    branches: main
+  pull_request:
+
+jobs:
+  msrv:
+    runs-on: ubuntu-latest
+    name: MSRV
+    steps:
+      - name: Check out source repository
+        uses: actions/checkout@v4
+      - name: Install the latest stable Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+      - name: Install cargo msrv
+        run: cargo install cargo-msrv
+      - name: Verify MSRV
+        run: cargo msrv verify
diff --git a/Cargo.toml b/Cargo.toml
index b88f4c2..db933a2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,6 +10,7 @@ TODO
 documentation = "https://github.com/chrissimpkins/size"
 homepage = "https://github.com/chrissimpkins/size"
 repository = "https://github.com/chrissimpkins/size"
+rust-version = "1.70.0"
 
 [[bin]]
 name = "siz"