diff --git a/src/vmime/platforms/windows/windowsFile.cpp b/src/vmime/platforms/windows/windowsFile.cpp
index 6aa0fea8..0ab90b16 100644
--- a/src/vmime/platforms/windows/windowsFile.cpp
+++ b/src/vmime/platforms/windows/windowsFile.cpp
@@ -310,7 +310,7 @@ bool windowsFile::exists() const
 shared_ptr <vmime::utility::file> windowsFile::getParent() const
 {
 	if (m_path.isEmpty())
-		return NULL;
+		return null;
 	else
 		return make_shared <windowsFile>(m_path.getParent());
 }
diff --git a/src/vmime/platforms/windows/windowsHandler.cpp b/src/vmime/platforms/windows/windowsHandler.cpp
index 4bc32dae..7376606e 100644
--- a/src/vmime/platforms/windows/windowsHandler.cpp
+++ b/src/vmime/platforms/windows/windowsHandler.cpp
@@ -293,7 +293,7 @@ shared_ptr <vmime::utility::fileSystemFactory> windowsHandler::getFileSystemFact
 shared_ptr <vmime::utility::childProcessFactory> windowsHandler::getChildProcessFactory()
 {
 	// TODO: Not implemented
-	return (NULL);
+	return null;
 }
 
 #endif
diff --git a/src/vmime/platforms/windows/windowsSocket.cpp b/src/vmime/platforms/windows/windowsSocket.cpp
index d18fa1a1..a64498a6 100644
--- a/src/vmime/platforms/windows/windowsSocket.cpp
+++ b/src/vmime/platforms/windows/windowsSocket.cpp
@@ -498,7 +498,7 @@ shared_ptr <net::timeoutHandler> windowsSocket::getTimeoutHandler()
 
 shared_ptr <vmime::net::socket> windowsSocketFactory::create()
 {
-	shared_ptr <vmime::net::timeoutHandler> th = NULL;
+	shared_ptr <vmime::net::timeoutHandler> th;
 	return make_shared <windowsSocket>(th);
 }