--- src/corelib/io/qsettings.cpp.orig
+++ src/corelib/io/qsettings.cpp
@@ -487,7 +487,9 @@
         case QVariant::Double:
         case QVariant::KeySequence: {
             result = v.toString();
-            if (result.startsWith(QLatin1Char('@')))
+            if (result.contains(QChar::Null))
+                result = QLatin1String("@String(") + result + QLatin1Char(')');
+            else if (result.startsWith(QLatin1Char('@')))
                 result.prepend(QLatin1Char('@'));
             break;
         }
@@ -554,6 +556,8 @@
         if (s.endsWith(QLatin1Char(')'))) {
             if (s.startsWith(QLatin1String("@ByteArray("))) {
                 return QVariant(s.toLatin1().mid(11, s.size() - 12));
+            } else if (s.startsWith(QLatin1String("@String("))) {
+                return QVariant(s.midRef(8, s.size() - 9).toString());
             } else if (s.startsWith(QLatin1String("@Variant("))) {
 #ifndef QT_NO_DATASTREAM
                 QByteArray a(s.toLatin1().mid(9));
--- src/corelib/io/qsettings_mac.cpp.orig
+++ src/corelib/io/qsettings_mac.cpp
@@ -218,7 +218,14 @@
     case QVariant::String:
     string_case:
     default:
-        result = QCFString::toCFStringRef(QSettingsPrivate::variantToString(value));
+        QString string = QSettingsPrivate::variantToString(value);
+        if (string.contains(QChar::Null)) {
+            QByteArray ba = string.toUtf8();
+            result = CFDataCreate(kCFAllocatorDefault, reinterpret_cast<const UInt8 *>(ba.data()),
+                                  CFIndex(ba.size()));
+        } else {
+            result = QCFString::toCFStringRef(string);
+        }
     }
     return result;
 }
@@ -269,8 +276,17 @@
         return (bool)CFBooleanGetValue(static_cast<CFBooleanRef>(cfvalue));
     } else if (typeId == CFDataGetTypeID()) {
         CFDataRef cfdata = static_cast<CFDataRef>(cfvalue);
-        return QByteArray(reinterpret_cast<const char *>(CFDataGetBytePtr(cfdata)),
-                          CFDataGetLength(cfdata));
+        QByteArray byteArray = QByteArray(reinterpret_cast<const char *>(CFDataGetBytePtr(cfdata)),
+                                          CFDataGetLength(cfdata));
+
+        // Fast-path for QByteArray, so that we don't have to go
+        // though the expensive and lossy conversion via UTF-8.
+        if (!byteArray.startsWith('@'))
+            return byteArray;
+
+        const QString str = QString::fromUtf8(byteArray.constData(), byteArray.size());
+        return QSettingsPrivate::stringToVariant(str);
+
     } else if (typeId == CFDictionaryGetTypeID()) {
         CFDictionaryRef cfdict = static_cast<CFDictionaryRef>(cfvalue);
         CFTypeID arrayTypeId = CFArrayGetTypeID();