diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index f170b20..9d646b2 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -973,7 +973,7 @@
   if (bMainXRef) {
     m_pTrailer = ToDictionary(pStream->GetDict()->Clone());
     ShrinkObjectMap(size);
-    for (auto it : m_ObjectInfo)
+    for (auto& it : m_ObjectInfo)
       it.second.type = 0;
   } else {
     m_Trailers.Add(ToDictionary(pStream->GetDict()->Clone()));