diff --git a/src/gsiqt/gsiqt.pro b/src/gsiqt/gsiqt.pro
index a252b470f..8e0f734e4 100644
--- a/src/gsiqt/gsiqt.pro
+++ b/src/gsiqt/gsiqt.pro
@@ -2,7 +2,7 @@
 TEMPLATE = subdirs
 SUBDIRS = qtbasic 
 
-equals(HAVE_QT5, "1") {
+greaterThan(QT_MAJOR_VERSION, 4) {
   SUBDIRS += qt5
   qt5.depends += qtbasic
 } else {
diff --git a/src/klayout.pri b/src/klayout.pri
index 550c0cba7..01e08ba06 100644
--- a/src/klayout.pri
+++ b/src/klayout.pri
@@ -178,7 +178,7 @@ equals(HAVE_QT, "0") {
     }
   }
 
-  equals(HAVE_QT5, "1") {
+  greaterThan(QT_MAJOR_VERSION, 4) {
 
     QT += widgets gui printsupport xmlpatterns
 
diff --git a/src/klayout_main/klayout_main/klayout_main.pro b/src/klayout_main/klayout_main/klayout_main.pro
index 31ab7eb22..695f11e88 100644
--- a/src/klayout_main/klayout_main/klayout_main.pro
+++ b/src/klayout_main/klayout_main/klayout_main.pro
@@ -45,7 +45,7 @@ equals(HAVE_QTBINDINGS, "1") {
     LIBS += -lklayout_QtUiTools
   }
 
-  equals(HAVE_QT5, "1") {
+  greaterThan(QT_MAJOR_VERSION, 4) {
 
     LIBS += -lklayout_QtWidgets
 
diff --git a/src/lay/lay/lay.pro b/src/lay/lay/lay.pro
index 8a07f7da3..dea36e8e7 100644
--- a/src/lay/lay/lay.pro
+++ b/src/lay/lay/lay.pro
@@ -207,7 +207,7 @@ equals(HAVE_QTBINDINGS, "1") {
   !equals(HAVE_QT_XML, "0") {
     LIBS += -lklayout_QtXml
   }
-  equals(HAVE_QT5, "1") {
+  greaterThan(QT_MAJOR_VERSION, 4) {
     LIBS += -lklayout_QtWidgets
   }
 }
diff --git a/src/laybasic/laybasic/laybasic.pro b/src/laybasic/laybasic/laybasic.pro
index 5cf65cefe..309e33a20 100644
--- a/src/laybasic/laybasic/laybasic.pro
+++ b/src/laybasic/laybasic/laybasic.pro
@@ -310,7 +310,7 @@ DEPENDPATH += $$QTBASIC_INC
 
 equals(HAVE_QTBINDINGS, "1") {
   LIBS += -lklayout_qtbasic -lklayout_QtGui -lklayout_QtCore
-  equals(HAVE_QT5, "1") {
+  greaterThan(QT_MAJOR_VERSION, 4) {
     LIBS += -lklayout_QtWidgets
   }
 }
diff --git a/src/lib_ut.pri b/src/lib_ut.pri
index 92abe0854..e80c7ba32 100644
--- a/src/lib_ut.pri
+++ b/src/lib_ut.pri
@@ -17,7 +17,7 @@ win32 {
   QMAKE_POST_LINK += $(COPY) $(DESTDIR)$(TARGET) $$DESTDIR_UT/$${TARGET}.ut
 }
 
-equals(HAVE_QT5, "1") {
+greaterThan(QT_MAJOR_VERSION, 4) {
   QT += testlib
 } else {
   CONFIG += qtestlib
diff --git a/src/plugins/tools/view_25d/view_25d.pro b/src/plugins/tools/view_25d/view_25d.pro
index 3eb5a6fad..138f0890d 100644
--- a/src/plugins/tools/view_25d/view_25d.pro
+++ b/src/plugins/tools/view_25d/view_25d.pro
@@ -3,7 +3,7 @@ TEMPLATE = subdirs
 
 contains(QT_CONFIG, opengl) {
 
-  equals(HAVE_QT5, "1") {
+  greaterThan(QT_MAJOR_VERSION, 4) {
     SUBDIRS = lay_plugin unit_tests
   }
 
diff --git a/src/pymod/QtCore/QtCore.pro b/src/pymod/QtCore/QtCore.pro
index b45334bd4..9f7943d23 100644
--- a/src/pymod/QtCore/QtCore.pro
+++ b/src/pymod/QtCore/QtCore.pro
@@ -10,6 +10,6 @@ HEADERS += \
 
 LIBS += -lklayout_QtCore -lklayout_QtGui
 
-equals(HAVE_QT5, "1") {
+greaterThan(QT_MAJOR_VERSION, 4) {
   LIBS += -lklayout_QtWidgets
 }
diff --git a/src/pymod/QtGui/QtGui.pro b/src/pymod/QtGui/QtGui.pro
index a2f39a5bc..287a0a072 100644
--- a/src/pymod/QtGui/QtGui.pro
+++ b/src/pymod/QtGui/QtGui.pro
@@ -10,7 +10,7 @@ HEADERS += \
 
 LIBS += -lklayout_QtGui -lklayout_QtCore
 
-equals(HAVE_QT5, "1") {
+greaterThan(QT_MAJOR_VERSION, 4) {
   LIBS += -lklayout_QtWidgets
 }
 
diff --git a/src/pymod/QtXml/QtXml.pro b/src/pymod/QtXml/QtXml.pro
index a8641948a..0e178a75e 100644
--- a/src/pymod/QtXml/QtXml.pro
+++ b/src/pymod/QtXml/QtXml.pro
@@ -13,6 +13,6 @@ LIBS += -lklayout_QtCore -lklayout_QtXml
 # Because of stupid dependency of QtCore on QtGui and this on QtWidgets:
 LIBS += -lklayout_QtGui
 
-equals(HAVE_QT5, "1") {
+greaterThan(QT_MAJOR_VERSION, 4) {
   LIBS += -lklayout_QtWidgets
 }
diff --git a/src/pymod/pymod.pro b/src/pymod/pymod.pro
index 1b1998702..7b140159f 100644
--- a/src/pymod/pymod.pro
+++ b/src/pymod/pymod.pro
@@ -18,7 +18,7 @@ SUBDIRS = \
       QtCore \
       QtGui
 
-    equals(HAVE_QT5, "1") {
+    greaterThan(QT_MAJOR_VERSION, 4) {
 
       SUBDIRS += QtWidgets
 
diff --git a/src/pymod/tl/tl.pro b/src/pymod/tl/tl.pro
index 2ae8a8b1f..58219f4a0 100644
--- a/src/pymod/tl/tl.pro
+++ b/src/pymod/tl/tl.pro
@@ -12,7 +12,7 @@ HEADERS += \
 # Use this opportunity to provide the __init__.py file
 
 equals(HAVE_QTBINDINGS, "1") {
-  equals(HAVE_QT5, "1") {
+  greaterThan(QT_MAJOR_VERSION, 4) {
     INIT_PY = $$PWD/../__init__.py.qt5
   } else {
     INIT_PY = $$PWD/../__init__.py.qt4
diff --git a/src/unit_tests/unit_tests.pro b/src/unit_tests/unit_tests.pro
index 1676e614a..0e01149cb 100644
--- a/src/unit_tests/unit_tests.pro
+++ b/src/unit_tests/unit_tests.pro
@@ -37,7 +37,7 @@ LIBS += -lklayout_gsi_test
     !equals(HAVE_QT_XML, "0") {
       LIBS += -lklayout_QtXml
     }
-    equals(HAVE_QT5, "1") {
+    greaterThan(QT_MAJOR_VERSION, 4) {
       LIBS += -lklayout_QtWidgets
     }
   }