diff --git a/src_main/core/pistring.h b/src_main/core/pistring.h
index bedf510b..931b2a7f 100755
--- a/src_main/core/pistring.h
+++ b/src_main/core/pistring.h
@@ -47,7 +47,7 @@ public:
 	PIString & operator +=(const PIChar & c) {push_back(c); return *this;}
 	PIString & operator +=(const char * str);
 	PIString & operator +=(const wchar_t * str);
-	PIString & operator +=(const PIByteArray & ba) {appendFromChars((const char * )ba.data(), ba.size_s()); return *this;}
+	PIString & operator +=(const PIByteArray & ba) {appendFromChars((const char * )ba.data(), ba.size_s(), __utf8name__); return *this;}
 	PIString & operator +=(const PIString & str);
 
 	//PIString(const char c) {*this += c;}