diff --git a/src/chatdlg.h b/src/chatdlg.h
index 0dab792a..a7f3ecbf 100755
--- a/src/chatdlg.h
+++ b/src/chatdlg.h
@@ -30,11 +30,11 @@
 #include <QLayout>
 #include <QAccessible>
 #include "global.h"
-#ifdef _WIN32
-# include "../windows/moc/chatdlgbase.h"
+#ifdef _IS_QMAKE_CONFIG
+# include "ui_chatdlgbase.h"
 #else
-# ifdef _IS_QMAKE_CONFIG
-#  include "ui_chatdlgbase.h"
+# ifdef _WIN32
+#  include "../windows/moc/chatdlgbase.h" // required if llcon.sln and MocQT.bat are used
 # else
 #  include "moc/chatdlgbase.h"
 # endif
diff --git a/src/clientsettingsdlg.h b/src/clientsettingsdlg.h
index 44118c23..66d1356b 100755
--- a/src/clientsettingsdlg.h
+++ b/src/clientsettingsdlg.h
@@ -37,11 +37,11 @@
 #include "global.h"
 #include "client.h"
 #include "multicolorled.h"
-#ifdef _WIN32
-# include "../windows/moc/clientsettingsdlgbase.h"
+#ifdef _IS_QMAKE_CONFIG
+# include "ui_clientsettingsdlgbase.h"
 #else
-# ifdef _IS_QMAKE_CONFIG
-#  include "ui_clientsettingsdlgbase.h"
+# ifdef _WIN32
+#  include "../windows/moc/clientsettingsdlgbase.h" // required if llcon.sln and MocQT.bat are used
 # else
 #  include "moc/clientsettingsdlgbase.h"
 # endif
diff --git a/src/connectdlg.h b/src/connectdlg.h
index 398b3339..b6f52694 100755
--- a/src/connectdlg.h
+++ b/src/connectdlg.h
@@ -31,11 +31,11 @@
 #include <QLocale>
 #include "global.h"
 #include "client.h"
-#ifdef _WIN32
-# include "../windows/moc/connectdlgbase.h"
+#ifdef _IS_QMAKE_CONFIG
+# include "ui_connectdlgbase.h"
 #else
-# ifdef _IS_QMAKE_CONFIG
-#  include "ui_connectdlgbase.h"
+# ifdef _WIN32
+#  include "../windows/moc/connectdlgbase.h" // required if llcon.sln and MocQT.bat are used
 # else
 #  include "moc/connectdlgbase.h"
 # endif
diff --git a/src/llconclientdlg.h b/src/llconclientdlg.h
index 37fac06a..75a84d45 100755
--- a/src/llconclientdlg.h
+++ b/src/llconclientdlg.h
@@ -41,11 +41,11 @@
 #include "clientsettingsdlg.h"
 #include "chatdlg.h"
 #include "connectdlg.h"
-#ifdef _WIN32
-# include "../windows/moc/llconclientdlgbase.h"
+#ifdef _IS_QMAKE_CONFIG
+# include "ui_llconclientdlgbase.h"
 #else
-# ifdef _IS_QMAKE_CONFIG
-#  include "ui_llconclientdlgbase.h"
+# ifdef _WIN32
+#  include "../windows/moc/llconclientdlgbase.h" // required if llcon.sln and MocQT.bat are used
 # else
 #  include "moc/llconclientdlgbase.h"
 # endif
diff --git a/src/llconserverdlg.h b/src/llconserverdlg.h
index 9cd1ad63..c6361ba3 100755
--- a/src/llconserverdlg.h
+++ b/src/llconserverdlg.h
@@ -37,11 +37,11 @@
 #include "server.h"
 #include "settings.h"
 #include "multicolorled.h"
-#ifdef _WIN32
-# include "../windows/moc/llconserverdlgbase.h"
+#ifdef _IS_QMAKE_CONFIG
+# include "ui_llconserverdlgbase.h"
 #else
-# ifdef _IS_QMAKE_CONFIG
-#  include "ui_llconserverdlgbase.h"
+# ifdef _WIN32
+#  include "../windows/moc/llconserverdlgbase.h" // required if llcon.sln and MocQT.bat are used
 # else
 #  include "moc/llconserverdlgbase.h"
 # endif
diff --git a/src/util.h b/src/util.h
index db93b361..e894f3b8 100755
--- a/src/util.h
+++ b/src/util.h
@@ -40,12 +40,15 @@
 #include "global.h"
 using namespace std; // because of the library: "vector"
 #ifdef _WIN32
-# include "../windows/moc/aboutdlgbase.h"
+# define NOMINMAX // solves a compiler error in qdatetime.h (Qt5)
 # include <windows.h>
 # include <mmsystem.h>
+#endif
+#ifdef _IS_QMAKE_CONFIG
+# include "ui_aboutdlgbase.h"
 #else
-# ifdef _IS_QMAKE_CONFIG
-#  include "ui_aboutdlgbase.h"
+# ifdef _WIN32
+#  include "../windows/moc/aboutdlgbase.h" // required if llcon.sln and MocQT.bat are used
 # else
 #  include "moc/aboutdlgbase.h"
 # endif
diff --git a/windows/sound.h b/windows/sound.h
index 28c1863f..716e632e 100755
--- a/windows/sound.h
+++ b/windows/sound.h
@@ -25,6 +25,7 @@
 #if !defined ( _SOUNDIN_H__9518A621_7F78_11D3_8C0D_EEBF182CF549__INCLUDED_ )
 #define _SOUNDIN_H__9518A621_7F78_11D3_8C0D_EEBF182CF549__INCLUDED_
 
+#define NOMINMAX // solves a compiler error in qdatetime.h (Qt5)
 #include <windows.h>
 #include <QMutex>
 #include <QMessageBox>