diff --git a/Data/ODBC/include/Poco/Data/ODBC/Preparator.h b/Data/ODBC/include/Poco/Data/ODBC/Preparator.h
index 586c14498..a9246cd15 100644
--- a/Data/ODBC/include/Poco/Data/ODBC/Preparator.h
+++ b/Data/ODBC/include/Poco/Data/ODBC/Preparator.h
@@ -633,7 +633,7 @@ private:
 			(SQLUSMALLINT) pos + 1, 
 			valueType, 
 			(SQLPOINTER) pCache, 
-			(SQLINTEGER) size, 
+			(SQLINTEGER) size*sizeof(T), 
 			&_lengths[pos])))
 		{
 			throw StatementException(_rStmt, "SQLBindCol()");
@@ -1040,7 +1040,7 @@ inline void Preparator::prepare(std::size_t pos, const std::list<std::string>& v
 
 inline void Preparator::prepare(std::size_t pos, const UTF16String&)
 {
-	prepareVariableLen<UTF16String::value_type>(pos, SQL_C_WCHAR, maxDataSize(pos), DT_CHAR);
+	prepareVariableLen<UTF16String::value_type>(pos, SQL_C_WCHAR, maxDataSize(pos), DT_WCHAR);
 }