diff --git a/src/AddDeviceWizard.cpp b/src/AddDeviceWizard.cpp
index 911f17c79..2ddf598fb 100644
--- a/src/AddDeviceWizard.cpp
+++ b/src/AddDeviceWizard.cpp
@@ -202,7 +202,9 @@ DeviceScanner::quickScan(bool deep) // scan quickly or if true scan forever, as
 
     // we will need a factory for this soon..
     case DEV_CT : wizard->controller = new ComputrainerController(NULL, NULL); break;
+#if QT_VERSION >= 0x050000
     case DEV_MONARK : wizard->controller = new MonarkController(NULL, NULL); break;
+#endif
 #ifdef GC_HAVE_LIBUSB
     case DEV_FORTIUS : wizard->controller = new FortiusController(NULL, NULL); break;
 #endif
diff --git a/src/AddDeviceWizard.h b/src/AddDeviceWizard.h
index aa02e92e7..2da8f3e29 100644
--- a/src/AddDeviceWizard.h
+++ b/src/AddDeviceWizard.h
@@ -32,7 +32,9 @@
 #include "FortiusController.h"
 #endif
 #include "ComputrainerController.h"
+#if QT_VERSION >= 0x050000
 #include "MonarkController.h"
+#endif
 #include "ANTlocalController.h"
 #include "ANTChannel.h"
 #include "NullController.h"
diff --git a/src/DeviceTypes.cpp b/src/DeviceTypes.cpp
index d5efdeb9c..832d0d16d 100644
--- a/src/DeviceTypes.cpp
+++ b/src/DeviceTypes.cpp
@@ -56,9 +56,11 @@ DeviceTypes::DeviceTypes()
         tr("Racermate Computrainer Lab or Pro bike trainer with the handlebar controller "
         "connected via a USB adaptor or directly connected to a local serial port.") ,
         ":images/devices/computrainer.png"                                        },
+#if QT_VERSION >= 0x050000
       { DEV_MONARK,       DEV_SERIAL,  (char *) "Monark LTx/LCx",true,    false,
         tr("Monark USB device ") ,
         ":images/devices/monark_lt2.png"                                        },
+#endif
 #ifdef GC_HAVE_LIBUSB
       { DEV_FORTIUS,  DEV_LIBUSB,  (char *) "Tacx Fortius",          true,    false,
         tr("Tacx Fortius/iMagic bike trainer with the handlebar controller connected "
diff --git a/src/src.pro b/src/src.pro
index 356e2a39e..345569d68 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -21,7 +21,7 @@ LIBS += -lm $${LIBZ_LIBS}
 #            5.2.0 or higher
 #
 ## common modules
-QT += xml sql network script svg concurrent serialport
+QT += xml sql network script svg concurrent
 
 lessThan(QT_MAJOR_VERSION, 5) {
 
@@ -31,7 +31,7 @@ lessThan(QT_MAJOR_VERSION, 5) {
 } else {
 
     ## QT5 specific modules
-    QT += webkitwidgets widgets concurrent
+    QT += webkitwidgets widgets concurrent serialport
     macx {
         QT += macextras webenginewidgets
     } else {
@@ -41,6 +41,10 @@ lessThan(QT_MAJOR_VERSION, 5) {
     ## QT5 can support complex JSON documents
     SOURCES += Dropbox.cpp
     HEADERS += Dropbox.h
+
+    ## Monark support needs QtSerialPort
+    SOURCES += Monark.cpp MonarkController.cpp MonarkConnection.cpp
+    HEADERS += Monark.h MonarkController.h MonarkConnection.h
 }
 
 # if we are building in debug mode
@@ -455,9 +459,6 @@ HEADERS += \
         RealtimeController.h \
         ReferenceLineDialog.h \
         ComputrainerController.h \
-        MonarkConnection.h \
-        MonarkController.h \
-        Monark.h \
         RealtimePlot.h \
         RideAutoImportConfig.h \
         RideCache.h \
@@ -705,9 +706,6 @@ SOURCES += \
         RealtimeData.cpp \
         RealtimeController.cpp \
         ComputrainerController.cpp \
-        MonarkConnection.cpp \
-        MonarkController.cpp \
-        Monark.cpp \
         RealtimePlot.cpp \
         RealtimePlotWindow.cpp \
         ReferenceLineDialog.cpp \