diff --git a/src/common/init.cpp b/src/common/init.cpp
index 8b11d75ce1..08a51de755 100644
--- a/src/common/init.cpp
+++ b/src/common/init.cpp
@@ -218,6 +218,18 @@ static void FreeConvertedArgs()
 // initialization which is always done (not customizable) before wxApp creation
 static bool DoCommonPreInit()
 {
+#if wxUSE_UNICODE && defined(__WXOSX__)
+    // In OS X and iOS, wchar_t CRT functions convert to char* and fail under
+    // some locales. The safest fix is to set LC_CTYPE to UTF-8 to ensure that
+    // they can handle any input.
+    //
+    // Note that this must be done for any app, Cocoa or console, whether or
+    // not it uses wxLocale.
+    //
+    // See http://stackoverflow.com/questions/11713745/why-does-the-printf-family-of-functions-care-about-locale
+    setlocale(LC_CTYPE, "UTF-8");
+#endif // wxUSE_UNICODE && defined(__WXOSX__)
+
 #if wxUSE_LOG
     // Reset logging in case we were cleaned up and are being reinitialized.
     wxLog::DoCreateOnDemand();