diff -rupN --no-dereference podofo-0.9.7/src/podofo/base/PdfParser.h podofo-0.9.7-new/src/podofo/base/PdfParser.h
--- podofo-0.9.7/src/podofo/base/PdfParser.h	2020-03-27 17:53:35.000000000 +0100
+++ podofo-0.9.7-new/src/podofo/base/PdfParser.h	2021-01-09 20:24:45.356918625 +0100
@@ -39,7 +39,7 @@
 #include "PdfVecObjects.h"
 
 #define W_ARRAY_SIZE 3
-#define W_MAX_BYTES  4
+#define W_MAX_BYTES  8
 
 namespace PoDoFo {
 
diff -rupN --no-dereference podofo-0.9.7/src/podofo/base/PdfXRefStreamParserObject.cpp podofo-0.9.7-new/src/podofo/base/PdfXRefStreamParserObject.cpp
--- podofo-0.9.7/src/podofo/base/PdfXRefStreamParserObject.cpp	2020-10-10 19:17:47.000000000 +0200
+++ podofo-0.9.7-new/src/podofo/base/PdfXRefStreamParserObject.cpp	2021-01-09 20:24:45.356918625 +0100
@@ -237,7 +237,7 @@ void PdfXRefStreamParserObject::ReadXRef
 {
     int              i;
     pdf_int64        z;
-    unsigned long    nData[W_ARRAY_SIZE];
+    pdf_uint64       nData[W_ARRAY_SIZE];
 
     for( i=0;i<W_ARRAY_SIZE;i++ )
     {
@@ -253,7 +253,8 @@ void PdfXRefStreamParserObject::ReadXRef
         nData[i] = 0;
         for( z=W_MAX_BYTES-lW[i];z<W_MAX_BYTES;z++ )
         {
-            nData[i] = (nData[i] << 8) + static_cast<unsigned char>(*pBuffer);
+            nData[i] <<= 8;
+            nData[i] += static_cast<unsigned char>(*pBuffer);
             ++pBuffer;
         }
     }
diff -rupN --no-dereference podofo-0.9.7/src/podofo/base/PdfXRefStreamParserObject.h podofo-0.9.7-new/src/podofo/base/PdfXRefStreamParserObject.h
--- podofo-0.9.7/src/podofo/base/PdfXRefStreamParserObject.h	2019-05-23 12:08:59.000000000 +0200
+++ podofo-0.9.7-new/src/podofo/base/PdfXRefStreamParserObject.h	2021-01-09 20:24:45.356918625 +0100
@@ -38,7 +38,7 @@
 #include "PdfParserObject.h"
 
 #define W_ARRAY_SIZE 3
-#define W_MAX_BYTES  4
+#define W_MAX_BYTES  8
 
 namespace PoDoFo {