diff --git a/CHANGELOG.md b/CHANGELOG.md
index cac39d6..bb04fd4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@
 
 - Drop support against end-of-lifed Node.js versions (v16 and earlier) ([#291](https://github.com/marp-team/marpit/issues/291), [#380](https://github.com/marp-team/marpit/pull/380))
 
+### Added
+
+- Add `-webkit-text-size-adjust: 100%;` to the scaffold theme ([#389](https://github.com/marp-team/marpit/pull/389))
+
 ### Removed
 
 - Deprecated color setting shorthand via Markdown image syntax ([#331](https://github.com/marp-team/marpit/issues/331), [#379](https://github.com/marp-team/marpit/pull/379))
diff --git a/src/theme/scaffold.js b/src/theme/scaffold.js
index 239ad36..60731c8 100644
--- a/src/theme/scaffold.js
+++ b/src/theme/scaffold.js
@@ -12,6 +12,9 @@ section {
   position: relative;
 
   scroll-snap-align: center center;
+
+  -webkit-text-size-adjust: 100%;
+  text-size-adjust: 100%;
 }
 
 section::after {