diff --git a/src/static/js/Changeset.js b/src/static/js/Changeset.js
index ad9f5b0a0db9..13dc4dfc585a 100644
--- a/src/static/js/Changeset.js
+++ b/src/static/js/Changeset.js
@@ -976,8 +976,9 @@ class TextLinesMutator {
         this._curLine += newLines.length;
         // insert the remaining chars from the "old" line (e.g. the line we were in
         // when we started to insert new lines)
-        this._curSplice.push(theLine.substring(lineCol));
-        this._curCol = 0; // TODO(doc) why is this not set to the length of last line?
+        const remaining = theLine.substring(lineCol);
+        if (remaining !== '') this._curSplice.push(remaining);
+        this._curCol = 0;
       } else {
         this._curSplice.push(...newLines);
         this._curLine += newLines.length;
diff --git a/src/tests/frontend/specs/easysync-mutations.js b/src/tests/frontend/specs/easysync-mutations.js
index 27c4a1e5d59c..3208858b9dae 100644
--- a/src/tests/frontend/specs/easysync-mutations.js
+++ b/src/tests/frontend/specs/easysync-mutations.js
@@ -179,6 +179,11 @@ describe('easysync-mutations', function () {
     ['insert', 'c'],
   ], ['fun\n', 'c']);
 
+  runMutationTest(14, ['\n'], [
+    ['remove', 1, 1, '\n'],
+    ['insert', 'a'],
+    ['insert', 'c\n', 1],
+  ], ['ac\n']);
   it('mutatorHasMore', async function () {
     const lines = ['1\n', '2\n', '3\n', '4\n'];
     let mu;