diff --git a/packages/block-editor/src/components/rich-text/index.js b/packages/block-editor/src/components/rich-text/index.js
index 6c5502b223dfc..2d1a7eced0730 100644
--- a/packages/block-editor/src/components/rich-text/index.js
+++ b/packages/block-editor/src/components/rich-text/index.js
@@ -117,7 +117,7 @@ function RichTextWrapper(
 		onRemove,
 		onMerge,
 		onSplit,
-		onSplitAtEnd,
+		__unstableOnSplitAtEnd: onSplitAtEnd,
 		__unstableOnSplitMiddle: onSplitMiddle,
 		identifier,
 		// To do: find a better way to implicitly inherit props.
@@ -361,7 +361,7 @@ function RichTextWrapper(
 				} else {
 					onChange( insertLineSeparator( value ) );
 				}
-			} else if ( shiftKey ) {
+			} else if ( shiftKey || ( ! canSplit && ! onSplitAtEnd ) ) {
 				if ( ! disableLineBreaks ) {
 					onChange( insert( value, '\n' ) );
 				}
diff --git a/packages/block-library/src/image/edit.js b/packages/block-library/src/image/edit.js
index 4eab713a47987..71bcb8d0fe432 100644
--- a/packages/block-library/src/image/edit.js
+++ b/packages/block-library/src/image/edit.js
@@ -673,7 +673,7 @@ export class ImageEdit extends Component {
 							}
 							isSelected={ this.state.captionFocused }
 							inlineToolbar
-							onSplitAtEnd={ () =>
+							__unstableOnSplitAtEnd={ () =>
 								insertBlocksAfter(
 									createBlock( 'core/paragraph' )
 								)