diff --git a/CHANGELOG.md b/CHANGELOG.md
index f9690d2..29493f2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-- Nothing yet!
+### Fixed
+
+- Include unit in `hr` border-width value ([#379](https://github.com/tailwindlabs/tailwindcss-typography/pull/379)
 
 ## [0.5.16] - 2025-01-07
 
diff --git a/src/styles.js b/src/styles.js
index a4d6967..42eb43d 100644
--- a/src/styles.js
+++ b/src/styles.js
@@ -1470,7 +1470,7 @@ module.exports = {
         },
         hr: {
           borderColor: 'var(--tw-prose-hr)',
-          borderTopWidth: 1,
+          borderTopWidth: '1px',
         },
         blockquote: {
           fontWeight: '500',