diff --git a/packages/block-library/src/site-tagline/block.json b/packages/block-library/src/site-tagline/block.json
index 465db6cf757a9..7a69e6b1e22a9 100644
--- a/packages/block-library/src/site-tagline/block.json
+++ b/packages/block-library/src/site-tagline/block.json
@@ -31,6 +31,7 @@
 			"lineHeight": true,
 			"__experimentalFontFamily": true,
 			"__experimentalTextTransform": true,
+			"__experimentalTextDecoration": true,
 			"__experimentalFontStyle": true,
 			"__experimentalFontWeight": true,
 			"__experimentalLetterSpacing": true,
diff --git a/packages/block-library/src/site-title/block.json b/packages/block-library/src/site-title/block.json
index 63d9dff06cf09..717db27747d7f 100644
--- a/packages/block-library/src/site-title/block.json
+++ b/packages/block-library/src/site-title/block.json
@@ -47,6 +47,7 @@
 			"lineHeight": true,
 			"__experimentalFontFamily": true,
 			"__experimentalTextTransform": true,
+			"__experimentalTextDecoration": true,
 			"__experimentalFontStyle": true,
 			"__experimentalFontWeight": true,
 			"__experimentalLetterSpacing": true,