diff --git a/src/os/windows/win32.cpp b/src/os/windows/win32.cpp
--- a/src/os/windows/win32.cpp
+++ b/src/os/windows/win32.cpp
@@ -541,23 +541,21 @@ const char *GetCurrentLocale(const char 
 
 static WCHAR _cur_iso_locale[16] = L"";
 
-void Win32SetCurrentLocaleName(const char *iso_code)
+void Win32SetCurrentLocaleName(std::string iso_code)
 {
 	/* Convert the iso code into the format that windows expects. */
-	char iso[16];
-	if (strcmp(iso_code, "zh_TW") == 0) {
-		strecpy(iso, "zh-Hant", lastof(iso));
-	} else if (strcmp(iso_code, "zh_CN") == 0) {
-		strecpy(iso, "zh-Hans", lastof(iso));
+	if (iso_code == "zh_TW") {
+		iso_code = "zh-Hant";
+	} else if (iso_code == "zh_CN") {
+		iso_code = "zh-Hans";
 	} else {
 		/* Windows expects a '-' between language and country code, but we use a '_'. */
-		strecpy(iso, iso_code, lastof(iso));
-		for (char *c = iso; *c != '\0'; c++) {
-			if (*c == '_') *c = '-';
+		for (char &c : iso_code) {
+			if (c == '_') c = '-';
 		}
 	}
 
-	MultiByteToWideChar(CP_UTF8, 0, iso, -1, _cur_iso_locale, lengthof(_cur_iso_locale));
+	MultiByteToWideChar(CP_UTF8, 0, iso_code.c_str(), -1, _cur_iso_locale, lengthof(_cur_iso_locale));
 }
 
 int OTTDStringCompare(std::string_view s1, std::string_view s2)