diff --git a/src/core/PieceTable.cc b/src/core/PieceTable.cc
index c230879..2b113c2 100644
--- a/src/core/PieceTable.cc
+++ b/src/core/PieceTable.cc
@@ -345,13 +345,13 @@ void PieceTable::insertion_test(Cursor & c)
     m_append_buffer[m_append_buffer_index++] = 'z';
 
     Change * change = &m_changes_buffer[m_changes_buffer_index++];
-    change->links[0][0][0] = c.iterator.piece->prev;
-    change->links[0][0][1] = c.iterator.piece;
-    change->links[0][1][0] = c.iterator.piece;
-    change->links[0][1][1] = c.iterator.piece->next;
 
     if (c.iterator.valid())
     {
+        change->links[0][0][0] = c.iterator.piece->prev;
+        change->links[0][0][1] = c.iterator.piece;
+        change->links[0][1][0] = c.iterator.piece;
+        change->links[0][1][1] = c.iterator.piece->next;
         if (c.iterator.offset > 0u)
         {
             Piece * piece2 = add_piece();
@@ -395,6 +395,10 @@ void PieceTable::insertion_test(Cursor & c)
     }
     else
     {
+        change->links[0][0][0] = start_piece;
+        change->links[0][0][1] = end_piece;
+        change->links[0][1][0] = nullptr;
+        change->links[0][1][1] = nullptr;
         change->links[1][0][0] = start_piece;
         change->links[1][0][1] = piece;
         change->links[1][1][0] = piece;
@@ -419,6 +423,9 @@ void PieceTable::apply_change(Change * change, uint8_t forward)
 {
     change->links[forward][0][0]->next = change->links[forward][0][1];
     change->links[forward][0][1]->prev = change->links[forward][0][0];
-    change->links[forward][1][0]->next = change->links[forward][1][1];
-    change->links[forward][1][1]->prev = change->links[forward][1][0];
+    if (change->links[forward][1][0] != nullptr)
+    {
+        change->links[forward][1][0]->next = change->links[forward][1][1];
+        change->links[forward][1][1]->prev = change->links[forward][1][0];
+    }
 }