diff --git a/core/fpdfapi/edit/cpdf_creator.cpp b/core/fpdfapi/edit/cpdf_creator.cpp
index 71ef379..f2e4e24 100644
--- a/core/fpdfapi/edit/cpdf_creator.cpp
+++ b/core/fpdfapi/edit/cpdf_creator.cpp
@@ -618,7 +618,9 @@
   m_pIDArray->Add(m_pIDArray->GetObjectAt(0)->Clone());
   if (m_pEncryptDict) {
     ASSERT(m_pParser);
-    if (m_pEncryptDict->GetStringFor("Filter") == "Standard") {
+    int revision = m_pEncryptDict->GetIntegerFor("R");
+    if ((revision == 2 || revision == 3) &&
+        m_pEncryptDict->GetStringFor("Filter") == "Standard") {
       m_pNewEncryptDict = ToDictionary(m_pEncryptDict->Clone());
       m_pEncryptDict = m_pNewEncryptDict;
       m_pSecurityHandler = pdfium::MakeRetain<CPDF_SecurityHandler>();