--- a/frmts/pdf/pdfobject.cpp	2018-05-29 11:23:00.980957371 +0300
+++ b/frmts/pdf/pdfobject.cpp	2018-05-29 11:23:44.378955265 +0300
@@ -1055,7 +1055,7 @@
 {
     if (GetType() == PDFObjectType_String)
     {
-        GooString* gooString = m_po->getString();
+        GooString* gooString =(GooString*) m_po->getString();
         return (osStr = GDALPDFGetUTF8StringFromBytes(reinterpret_cast<const GByte*>(gooString->getCString()),
                                                       static_cast<int>(gooString->getLength())));
     }