diff --git a/source/range/InsertDelete.ts b/source/range/InsertDelete.ts
index c443bf9..f6f34d4 100644
--- a/source/range/InsertDelete.ts
+++ b/source/range/InsertDelete.ts
@@ -134,7 +134,7 @@ const extractContentsOfRange = (
     }
 
     // Merge text nodes if adjacent
-    node = endContainer.previousSibling;
+    node = endContainer && endContainer.previousSibling;
     if (node && node instanceof Text && endContainer instanceof Text) {
         endOffset = node.length;
         node.appendData(endContainer.data);