diff --git a/src/core/pibytearray.h b/src/core/pibytearray.h
index 062929b3..40c8af13 100755
--- a/src/core/pibytearray.h
+++ b/src/core/pibytearray.h
@@ -181,7 +181,7 @@ inline PIByteArray & operator <<(PIByteArray & s, const float v) {PBA_OPERATOR_T
 //! \relatesalso PIByteArray \brief Store operator
 inline PIByteArray & operator <<(PIByteArray & s, const double & v) {PBA_OPERATOR_TO return s;}
 //! \relatesalso PIByteArray \brief Store operator, see \ref PIByteArray_sec1 for details
-inline PIByteArray & operator <<(PIByteArray & s, const PIByteArray & v) {s << v.size_s(); int os = s.size_s(); s.enlarge(v.size_s()); if (v.size_s() > 0) memcpy(s.data(os), v.data(), v.size()); return s;}
+inline PIByteArray & operator <<(PIByteArray & s, const PIByteArray & v) {s << int(v.size_s()); int os = s.size_s(); s.enlarge(v.size_s()); if (v.size_s() > 0) memcpy(s.data(os), v.data(), v.size()); return s;}
 //! \relatesalso PIByteArray \brief Store operator, see \ref PIByteArray_sec1 for details
 inline PIByteArray & operator <<(PIByteArray & s, const PIByteArray::RawData & v) {int os = s.size_s(); s.enlarge(v.s); if (v.s > 0) memcpy(s.data(os), v.d, v.s); return s;}
 //! \relatesalso PIByteArray \brief Store operator
@@ -189,13 +189,13 @@ template<typename Type0, typename Type1>
 inline PIByteArray & operator <<(PIByteArray & s, const PIPair<Type0, Type1> & v) {s << v.first << v.second; return s;}
 //! \relatesalso PIByteArray \brief Store operator
 template<typename T>
-inline PIByteArray & operator <<(PIByteArray & s, const PIVector<T> & v) {s << v.size_s(); for (uint i = 0; i < v.size(); ++i) s << v[i]; return s;}
+inline PIByteArray & operator <<(PIByteArray & s, const PIVector<T> & v) {s << int(v.size_s()); for (uint i = 0; i < v.size(); ++i) s << v[i]; return s;}
 //! \relatesalso PIByteArray \brief Store operator
 template<typename T>
-inline PIByteArray & operator <<(PIByteArray & s, const PIList<T> & v) {s << v.size_s(); for (uint i = 0; i < v.size(); ++i) s << v[i]; return s;}
+inline PIByteArray & operator <<(PIByteArray & s, const PIList<T> & v) {s << int(v.size_s()); for (uint i = 0; i < v.size(); ++i) s << v[i]; return s;}
 //! \relatesalso PIByteArray \brief Store operator
 template<typename T>
-inline PIByteArray & operator <<(PIByteArray & s, const PIDeque<T> & v) {s << v.size_s(); for (uint i = 0; i < v.size(); ++i) s << v[i]; return s;}
+inline PIByteArray & operator <<(PIByteArray & s, const PIDeque<T> & v) {s << int(v.size_s()); for (uint i = 0; i < v.size(); ++i) s << v[i]; return s;}
 #ifdef PIP_BYTEARRAY_STREAM_ANY_TYPE
 template<typename T>
 inline PIByteArray & operator <<(PIByteArray & s, const T & v) {PBA_OPERATOR_TO return s;}