diff --git a/libs/main/core/pistring.cpp b/libs/main/core/pistring.cpp
index c8edb2db..3bfdf3c3 100644
--- a/libs/main/core/pistring.cpp
+++ b/libs/main/core/pistring.cpp
@@ -27,7 +27,9 @@
 #ifdef WINDOWS
 #  include <stringapiset.h>
 #endif
-#include <cuchar>
+#include <string>
+#include <locale>
+#include <codecvt>
 
 //! \addtogroup Core
 //! \{
@@ -207,17 +209,9 @@ void PIString::appendFromChars(const char * c, int s, const char * codepage) {
 	UConverter * cc = ucnv_open(codepage, &e);
 	if (cc) {
 		enlarge(s);
-//		UChar * ucs = new UChar[s];
-//		memset(ucs, 0, s * sizeof(UChar));
 		e = (UErrorCode)0;
 		int sz = ucnv_toUChars(cc, (UChar*)(PIDeque<PIChar>::data(old_sz)), s, c, s, &e);
-		//printf("appendFromChars %d -> %d\n", s, sz);
-		//printf("PIString %d -> %d\n", c[0], ucs[0]);
 		resize(old_sz+sz);
-//		for (int i = 0; i < sz; ++i) {
-//			push_back(PIChar((ushort)ucs[i]));
-//		}
-//		delete[] ucs;
 		ucnv_close(cc);
 		return;
 	}
@@ -227,40 +221,11 @@ void PIString::appendFromChars(const char * c, int s, const char * codepage) {
 	if (sz <= 0) return;
 	enlarge(sz);
 	MultiByteToWideChar((uint)(uintptr_t)codepage, MB_ERR_INVALID_CHARS, c, s, (LPWSTR)PIDeque<PIChar>::data(old_sz), sz);
-	return;
-	//printf("request %d\n", sz);
 #  else
-	std::mbstate_t state{};
-	PIChar c16;
-	int sz = 0;
-	while(std::size_t rc = std::mbrtoc16((char16_t*)&c16, c+sz, s - sz, &state)) {
-		if(rc == (std::size_t)-3)
-			append(c16);
-		else if(rc == (std::size_t)-2)
-			break;
-		else if(rc == (std::size_t)-1)
-			break;
-		else {
-			sz += rc;
-			append(c16);
-	}
-	}
-//	const char ** pc;
-//	char * c_ = nullptr;
-//	if (s > 0) {
-//		c_ = (char*)malloc(s+1);
-//		memcpy(c_, c, s);
-//		c_[s] = '\0';
-//		pc = (const char **)&c_;
-//	} else {
-//		pc = &c;
-//	}
-//	size_t len = mbsrtowcs(NULL, pc, 0, &state);
-//	wchar_t wstr[len+1];
-//	mbsrtowcs(&wstr[0], pc, len+1, &state);
-//	if (c_) free(c_);
-//	d.enlarge(len);
-//	for (size_t i=0; i<len; ++i) d[old_sz+i] = PIChar(wstr[i]);
+	std::wstring_convert<std::codecvt_utf8<char16_t>, char16_t> ucs2conv;
+	std::u16string ucs2 = ucs2conv.from_bytes(c, c+s);
+	enlarge(ucs2.size());
+	ucs2.copy((char16_t *)PIDeque<PIChar>::data(old_sz), ucs2.size());
 #  endif
 #endif
 }