diff --git a/Cargo.toml b/Cargo.toml
index 663afcb..84ce9fb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,11 +21,6 @@ appveyor = { repository = "mgeisler/version-sync" }
 codecov = { repository = "mgeisler/version-sync" }
 
 [dependencies]
-# This crate is compatible with Rust 2018, i.e., Rustc version 1.31.0.
-# Version requirements of dependencies can be bumped as long as the
-# dependencies compile with that compiler version. Some versions
-# requirements below an upper limit to indicate when the dependency
-# stops compiling with a Rust 2018 compatible compiler.
 pulldown-cmark = { version = "0.4, <0.5", default-features = false }
 semver-parser = "0.9"
 syn = { version = "1.0", features = ["full"] }
diff --git a/README.md b/README.md
index b25c2a6..aabda68 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,6 @@
 
 [![](https://img.shields.io/crates/v/version-sync.svg)][crates-io]
 [![](https://docs.rs/version-sync/badge.svg)][api-docs]
-[![](https://img.shields.io/badge/rustc-1.31.0-4d76ae.svg)][rust-2018]
 [![](https://travis-ci.org/mgeisler/version-sync.svg?branch=master)][travis-ci]
 [![](https://ci.appveyor.com/api/projects/status/github/mgeisler/version-sync?branch=master&svg=true)][appveyor]
 [![](https://codecov.io/gh/mgeisler/version-sync/branch/master/graph/badge.svg)][codecov]
@@ -109,6 +108,22 @@ your_crate = "0.1.2"
 
 This is a changelog describing the most important changes per release.
 
+### Unreleased
+
+Drop support for Rust 1.31.0 since our dependencies keep releasing new
+patch versions that push up the minimum required Rust version. These
+updates mean that `version-sync` 0.8.1 no longer compiles with Rust
+1.31.0 because `cargo sync` will pull in too new versions of the
+direct and transitive dependencies. This happens even if there are no
+changes in `version-sync`.
+
+The constant build failures in our CI makes it infeasible to keep
+`version-sync` compatible with any particular version of Rust. We will
+therefore track the latest stable version of Rust from now on.
+
+At the time of writing, the code compiles with Rust 1.36, but this
+will likely become outdated soon.
+
 ### Version 0.8.1 — April 3rd, 2019
 
 Dependencies were relaxed to make it easier to upgrade `version-sync`.
diff --git a/tests/version-numbers.rs b/tests/version-numbers.rs
index e39270d..01e6421 100644
--- a/tests/version-numbers.rs
+++ b/tests/version-numbers.rs
@@ -11,13 +11,6 @@ fn test_readme_changelog() {
     );
 }
 
-#[test]
-fn test_minimum_rustc_version() {
-    let version = r"1\.31\.0";
-    version_sync::assert_contains_regex!(".travis.yml", &format!(r"^  - {}", version));
-    version_sync::assert_contains_regex!("README.md", &format!("badge/rustc-{}", version));
-}
-
 #[test]
 fn test_html_root_url() {
     version_sync::assert_html_root_url_updated!("src/lib.rs");