diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a80ffa8..12a5736 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -28,7 +28,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        rust: [1.56.0, stable]
+        rust: [1.70.0, stable]
         os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps:
diff --git a/src/lib.rs b/src/lib.rs
index 5cdd20c..ea33e16 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -120,6 +120,10 @@
 //!   you [`KdlDocument::fmt`] in which case the original representation will be
 //!   thrown away and the actual value will be used when serializing.
 //!
+//! ## Minimum Supported Rust Version (MSRV)
+//! 
+//! This crate requires Rust 1.70.0 or later.
+//! 
 //! ## License
 //!
 //! The code in this repository is covered by [the Apache-2.0