diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index d5e513a1..3354b73e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -30,3 +30,17 @@ jobs:
           override: true
       - name: Test
         run: make test
+
+  build-old-stable:
+    name: Check on 1.51.0
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.51.0
+          profile: minimal
+          override: true
+      - name: Check
+        run: cargo check --no-default-features
diff --git a/Cargo.toml b/Cargo.toml
index d07df7a9..8d4f2467 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ license = "Apache-2.0"
 authors = ["Armin Ronacher <armin.ronacher@active-4.com>"]
 description = "A snapshot testing library for Rust"
 edition = "2018"
-rust-version = "1.56.1"
+rust-version = "1.51.0"
 homepage = "https://insta.rs/"
 repository = "https://github.com/mitsuhiko/insta"
 keywords = ["snapshot", "testing", "jest", "approval"]
diff --git a/README.md b/README.md
index 4ceabbfd..db605e15 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 [![Build Status](https://github.com/mitsuhiko/insta/workflows/Tests/badge.svg?branch=master)](https://github.com/mitsuhiko/insta/actions?query=workflow%3ATests)
 [![Crates.io](https://img.shields.io/crates/d/insta.svg)](https://crates.io/crates/insta)
 [![License](https://img.shields.io/github/license/mitsuhiko/insta)](https://github.com/mitsuhiko/insta/blob/master/LICENSE)
-[![rustc 1.56.1](https://img.shields.io/badge/rust-1.56.1%2B-orange.svg)](https://img.shields.io/badge/rust-1.56.1%2B-orange.svg)
+[![rustc 1.51.0](https://img.shields.io/badge/rust-1.51.0%2B-orange.svg)](https://img.shields.io/badge/rust-1.51.0%2B-orange.svg)
 [![Documentation](https://docs.rs/insta/badge.svg)](https://docs.rs/insta)
 [![VSCode Extension](https://img.shields.io/visual-studio-marketplace/v/mitsuhiko.insta?label=vscode%20extension)](https://marketplace.visualstudio.com/items?itemName=mitsuhiko.insta)