diff --git a/packages/rich-text/src/component/index.js b/packages/rich-text/src/component/index.js
index 76d8fc64d13268..d81d46bec76449 100644
--- a/packages/rich-text/src/component/index.js
+++ b/packages/rich-text/src/component/index.js
@@ -527,6 +527,12 @@ function RichText( {
 	function handleSpace( event ) {
 		const { keyCode, shiftKey, altKey, metaKey, ctrlKey } = event;
 
+		// Allow space characters to be typed in a <summary>.
+		if ( keyCode === SPACE && TagName === 'summary' ) {
+			handleChange( insert( createRecord(), ' ' ) );
+			return;
+		}
+
 		if (
 			// Only override when no modifiers are pressed.
 			shiftKey ||