diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index 1b6e29d..989843c 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -821,6 +821,7 @@
   gap_size_ += length;
 
   text_length_ -= length;
+  is_dirty_ = true;
   ClearSelection();
 
   if (delegate_)