diff --git a/packages/block-library/src/paragraph/edit.js b/packages/block-library/src/paragraph/edit.js
index e2ce500224dcea..983b92a1a15097 100644
--- a/packages/block-library/src/paragraph/edit.js
+++ b/packages/block-library/src/paragraph/edit.js
@@ -176,6 +176,7 @@ function ParagraphBlock( {
 						aria-label={ content ? __( 'Paragraph block' ) : __( 'Empty block; start writing or type forward slash to choose a block' ) }
 						placeholder={ placeholder || __( 'Start writing or type / to choose a block' ) }
 						__unstableEmbedURLOnPaste
+						__unstableAllowPrefixTransformations
 					/>
 				</TextColor>
 			</BackgroundColor>
diff --git a/packages/rich-text/src/component/index.js b/packages/rich-text/src/component/index.js
index 9984a7ac97695f..163d2ac59f84be 100644
--- a/packages/rich-text/src/component/index.js
+++ b/packages/rich-text/src/component/index.js
@@ -445,6 +445,7 @@ class RichText extends Component {
 		const {
 			__unstableInputRule: inputRule,
 			__unstableMarkAutomaticChange: markAutomaticChange,
+			__unstableAllowPrefixTransformations: allowPrefixTransformations,
 			formatTypes,
 			setTimeout,
 			clearTimeout,
@@ -454,6 +455,10 @@ class RichText extends Component {
 		clearTimeout( this.onInput.timeout );
 		this.onInput.timeout = setTimeout( this.onCreateUndoLevel, 1000 );
 
+		if ( ! allowPrefixTransformations ) {
+			return;
+		}
+
 		// Only run input rules when inserting text.
 		if ( inputType !== 'insertText' ) {
 			return;