diff --git a/Jamulus.pro b/Jamulus.pro
index b9fbd0dd..6cc6f0a4 100755
--- a/Jamulus.pro
+++ b/Jamulus.pro
@@ -13,10 +13,10 @@ CONFIG += qt \
 QT += network \
     xml
 
-!contains(CONFIG, "headless") {
-    QT += widgets
-} else {
+contains(CONFIG, "headless") {
     QT -= gui
+} else {
+    QT += widgets
 }
 
 TRANSLATIONS = src/res/translation/translation_de_DE.ts \
@@ -992,12 +992,12 @@ DISTFILES_OPUS += libs/opus/AUTHORS \
     libs/opus/celt/arm/armopts.s.in \
     libs/opus/celt/arm/celt_pitch_xcorr_arm.s \
 
-!contains(CONFIG, "headless") {
+contains(CONFIG, "headless") {
+    DEFINES += HEADLESS
+} else {
     HEADERS += $$HEADERS_GUI
     SOURCES += $$SOURCES_GUI
     FORMS += $$FORMS_GUI
-} else {
-    DEFINES += HEADLESS
 }
 
 # use external OPUS library if requested
diff --git a/src/main.cpp b/src/main.cpp
index 801be8e8..9a19c85f 100755
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -503,7 +503,7 @@ int main ( int argc, char** argv )
     }
 
 #ifdef HEADLESS
-    if (bUseGUI)
+    if ( bUseGUI )
     {
         bUseGUI = false;
         tsConsole << "No GUI support compiled. Running in headless mode." << endl;
@@ -538,8 +538,8 @@ int main ( int argc, char** argv )
     QCoreApplication* pApp = new QCoreApplication ( argc, argv );
 #else
     QCoreApplication* pApp = bUseGUI
-            ? new QApplication ( argc, argv )
-            : new QCoreApplication ( argc, argv );
+        ? new QApplication ( argc, argv )
+        : new QCoreApplication ( argc, argv );
 #endif
 
 #ifdef ANDROID
@@ -662,6 +662,7 @@ int main ( int argc, char** argv )
                              bDisconnectAllClientsOnQuit,
                              bUseDoubleSystemFrameSize,
                              eLicenceType );
+
 #ifndef HEADLESS
             if ( bUseGUI )
             {
diff --git a/src/soundbase.cpp b/src/soundbase.cpp
index 7d5adb4a..5e8a9702 100755
--- a/src/soundbase.cpp
+++ b/src/soundbase.cpp
@@ -22,10 +22,6 @@
  *
 \******************************************************************************/
 
-#ifndef HEADLESS
-# include <QMessageBox>
-#endif
-
 #include "soundbase.h"
 
 
diff --git a/src/soundbase.h b/src/soundbase.h
index fbd5883a..ab588a46 100755
--- a/src/soundbase.h
+++ b/src/soundbase.h
@@ -26,6 +26,9 @@
 
 #include <QThread>
 #include <QString>
+#ifndef HEADLESS
+# include <QMessageBox>
+#endif
 #include "global.h"
 #include "util.h"