diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index e1d9858a66..4d2b36632f 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -138,7 +138,7 @@ inline QChar QDirPrivate::getFilterSepChar(const QString &nameFilter)
 // static
 inline QStringList QDirPrivate::splitFilters(const QString &nameFilter, QChar sep)
 {
-    if (sep == 0)
+    if (sep.isNull())
         sep = getFilterSepChar(nameFilter);
     QStringList ret = nameFilter.split(sep);
     for (int i = 0; i < ret.count(); ++i)
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index e3a3cc79c6..ea220ed557 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -1509,7 +1509,7 @@ QString::QString(const QChar *unicode, int size)
     } else {
         if (size < 0) {
             size = 0;
-            while (unicode[size] != 0)
+            while (!unicode[size].isNull())
                 ++size;
         }
         if (!size) {