diff --git a/OOXML/Base/Unit.cpp b/OOXML/Base/Unit.cpp
index bbd808e890..ee2ebd23b7 100644
--- a/OOXML/Base/Unit.cpp
+++ b/OOXML/Base/Unit.cpp
@@ -877,72 +877,92 @@ namespace XmlUtils
 		}
 
 		return buffer;
-	}
-	std::wstring EncodeXmlString(const std::wstring& data, bool bDeleteNoUnicode)
-	{
-		std::wstring buffer;
-		buffer.reserve(data.size());
+    }
+    std::wstring EncodeXmlString(const std::wstring& data, bool bDeleteNoUnicode)
+    {
+        std::wstring buffer;
+        buffer.reserve(data.size());
 
-		if(bDeleteNoUnicode)
-		{
-			for(size_t pos = 0; pos < data.size(); ++pos)
-			{
-				switch(data[pos])
-				{
-				case '&':  buffer.append(L"&amp;");      break;
-				case '\"': buffer.append(L"&quot;");     break;
-				case '\'': buffer.append(L"&apos;");     break;
-				case '<':  buffer.append(L"&lt;");       break;
-				case '>':  buffer.append(L"&gt;");       break;
-				default:
-				{
-					if ( false == IsUnicodeSymbol( data[pos] ) )
-					{
-						wchar_t symbol1 = data[pos];
-						if(0xD800 <= symbol1 && symbol1 <= 0xDFFF && pos + 1 < data.size())
-						{
-							pos++;
-							wchar_t symbol2 = data[pos];
-							if (symbol1 < 0xDC00 && symbol2 >= 0xDC00 && symbol2 <= 0xDFFF)
-							{
-								buffer.append(&data[pos-1], 2);
-							}
-							else
-							{
-								buffer.append(L" ");
-							}
-						}
-						else
-						{
-							buffer.append(L" ");
-						}
-					}
-					else
-						buffer.append(&data[pos], 1);
-				}break;
-				}
-			}
-		}
-		else
-		{
-			for(size_t pos = 0; pos < data.size(); ++pos)
-			{
-				switch(data[pos])
-				{
-				case '&':  buffer.append(L"&amp;");      break;
-				case '\"': buffer.append(L"&quot;");     break;
-				case '\'': buffer.append(L"&apos;");     break;
-				case '<':  buffer.append(L"&lt;");       break;
-				case '>':  buffer.append(L"&gt;");       break;
-				case '\0':
-					return buffer;
-				default:   buffer.append(&data[pos], 1);	break;
-				}
-			}
-		}
+        if(bDeleteNoUnicode)
+        {
+            for (size_t pos = 0; pos < data.size(); ++pos)
+            {
+                switch (data[pos])
+                {
+                case L'&':  buffer.append(L"&amp;");  continue;
+                case L'\"': buffer.append(L"&quot;"); continue;
+                case L'\'': buffer.append(L"&apos;"); continue;
+                case L'<':  buffer.append(L"&lt;");   continue;
+                case L'>':  buffer.append(L"&gt;");   continue;
+                case L'\0':
+                default:
+                {
+                    if (!IsUnicodeSymbol(static_cast<unsigned int>( data[pos])))
+                    {
+#ifdef _WIN32
+                        wchar_t symbol1 = data[pos];
+#else
+                        uint16_t symbol1 = static_cast<uint16_t>(data[pos]);
+#endif
+
+                        if(0xD800 <= symbol1 && symbol1 <= 0xDFFF && pos + 1 < data.size())
+                        {
+#ifdef _WIN32
+                            wchar_t symbol2 = data[pos+1];
+#else
+                            uint16_t symbol2 = static_cast<uint16_t>(data[pos+1]);
+#endif
+                            if (symbol1 < 0xDC00 && symbol2 >= 0xDC00 && symbol2 <= 0xDFFF)
+                            {
+#ifdef _WIN32
+                                buffer.append(&data[pos], 2);
+#else
+                                uint32_t codepoint = 0x10000 + ((symbol1 - 0xD800) << 10) + (symbol2 - 0xDC00);
+                                buffer += static_cast<wchar_t>(codepoint);
+#endif
+                                pos++;
+                            }
+                            else
+                            {
+                                buffer.append(L" ");
+                            }
+                        }
+                        else
+                        {
+                            buffer.append(L" ");
+                        }
+                    }
+                    else
+                    {
+                        buffer.append(&data[pos], 1);
+                    }
+                }break;
+                }
+            }
+        }
+        else
+        {
+            for(size_t pos = 0; pos < data.size(); ++pos)
+            {
+                switch(data[pos])
+                {
+                case '&':  buffer.append(L"&amp;");      break;
+                case '\"': buffer.append(L"&quot;");     break;
+                case '\'': buffer.append(L"&apos;");     break;
+                case '<':  buffer.append(L"&lt;");       break;
+                case '>':  buffer.append(L"&gt;");       break;
+                case '\0':
+                    return buffer;
+                default:
+                    buffer.append(&data[pos], 1);	break;
+                }
+            }
+        }
+
+
+        return buffer;
+    }
 
-		return buffer;
-	}
 	std::wstring DeleteNonUnicode(const std::wstring& data)
 	{
 		std::wstring buffer;