diff --git a/aegisub/src/subtitles_provider_csri.cpp b/aegisub/src/subtitles_provider_csri.cpp
index 2aebb84b8..433451dab 100644
--- a/aegisub/src/subtitles_provider_csri.cpp
+++ b/aegisub/src/subtitles_provider_csri.cpp
@@ -44,6 +44,7 @@
 
 #include "ass_file.h"
 #include "subtitles_provider_csri.h"
+#include "text_file_writer.h"
 #include "video_context.h"
 
 
@@ -101,14 +102,14 @@ void CSRISubtitlesProvider::LoadSubtitles(AssFile *subs) {
 	// Open from memory
 	if (canOpenMem) {
 		std::vector<char> data;
-		subs->SaveMemory(data,_T("UTF-8"));
+		subs->SaveMemory(data,wxSTRING_ENCODING);
 		instance = csri_open_mem(renderer,&data[0],data.size(),NULL);
 	}
 
 	// Open from disk
 	else {
 		wxString subsFileName = VideoContext::Get()->GetTempWorkFile();
-		subs->Save(subsFileName,false,false,_T("UTF-8"));
+		subs->Save(subsFileName,false,false,wxSTRING_ENCODING);
 		instance = csri_open_file(renderer,subsFileName.mb_str(wxConvUTF8),NULL);
 	}
 }
diff --git a/aegisub/src/text_file_writer.cpp b/aegisub/src/text_file_writer.cpp
index 60d990b3d..d2b5abe43 100644
--- a/aegisub/src/text_file_writer.cpp
+++ b/aegisub/src/text_file_writer.cpp
@@ -63,7 +63,8 @@ TextFileWriter::TextFileWriter(wxString const& filename, wxString encoding)
 	}
 
 	if (encoding.empty()) encoding = lagi_wxString(OPT_GET("App/Save Charset")->GetString());
-	conv.reset(new agi::charset::IconvWrapper("utf-8", encoding.c_str(), true));
+	if (encoding.Lower() != wxSTRING_ENCODING)
+		conv.reset(new agi::charset::IconvWrapper(wxSTRING_ENCODING, encoding.c_str(), true));
 
 	// Write the BOM
 	try {
@@ -88,8 +89,15 @@ TextFileWriter::~TextFileWriter() {
 void TextFileWriter::WriteLineToFile(wxString line, bool addLineBreak) {
 	if (addLineBreak) line += L"\n";
 
-	std::string buf = conv->Convert(line.utf8_str().data());
-	file.write(buf.data(), buf.size());
+	// On non-windows this cast does nothing
+	const char *data = reinterpret_cast<const char *>(line.wx_str());
+	size_t len = line.size() * sizeof(wxStringCharType);
+
+	if (conv.get()) {
+		std::string buf = conv->Convert(std::string(data, len));
+		file.write(buf.data(), buf.size());
+	}
+	else {
+		file.write(data, len);
+	}
 }
-
-
diff --git a/aegisub/src/text_file_writer.h b/aegisub/src/text_file_writer.h
index 3b6de7c50..8a23a16ce 100644
--- a/aegisub/src/text_file_writer.h
+++ b/aegisub/src/text_file_writer.h
@@ -73,3 +73,11 @@ public:
 
 	void WriteLineToFile(wxString line, bool addLineBreak=true);
 };
+
+#if wxUSE_UNICODE_UTF8
+#define wxSTRING_ENCODING "utf-8"
+#elif defined(_WIN32)
+#define wxSTRING_ENCODING "utf-16le"
+#else
+#error wx must be built with wxUSE_UNICODE_UTF8
+#endif