Index: qwt-6.2.0/src/src.pro
===================================================================
--- qwt-6.2.0.orig/src/src.pro
+++ qwt-6.2.0/src/src.pro
@@ -82,14 +82,14 @@ contains(QWT_CONFIG, QwtPkgConfig) {
     greaterThan(QT_MAJOR_VERSION, 4) {
 
         QMAKE_PKGCONFIG_FILE = Qt$${QT_MAJOR_VERSION}$${QMAKE_PKGCONFIG_NAME}
-        QMAKE_PKGCONFIG_REQUIRES = Qt5Widgets Qt5Concurrent Qt5PrintSupport
+        QMAKE_PKGCONFIG_REQUIRES = Qt$${QT_MAJOR_VERSION}Widgets Qt$${QT_MAJOR_VERSION}Concurrent Qt$${QT_MAJOR_VERSION}PrintSupport
 
         contains(QWT_CONFIG, QwtSvg) {
-            QMAKE_PKGCONFIG_REQUIRES += Qt5Svg
+            QMAKE_PKGCONFIG_REQUIRES += Qt$${QT_MAJOR_VERSION}Svg
         }
 
         contains(QWT_CONFIG, QwtOpenGL) {
-            QMAKE_PKGCONFIG_REQUIRES += Qt5OpenGL
+            QMAKE_PKGCONFIG_REQUIRES += Qt$${QT_MAJOR_VERSION}OpenGL
         }
 
         QMAKE_DISTCLEAN += $${DESTDIR}/$${QMAKE_PKGCONFIG_DESTDIR}/$${QMAKE_PKGCONFIG_FILE}.pc
Index: qwt-6.2.0/qwt.prf
===================================================================
--- qwt-6.2.0.orig/qwt.prf
+++ qwt-6.2.0/qwt.prf
@@ -44,4 +44,9 @@ else {
 }   
 
 # QMAKE_RPATHDIR *= $${QWT_INSTALL_LIBS}
-qwtAddLibrary($${QWT_INSTALL_LIBS}, qwt)
+greaterThan(QT_MAJOR_VERSION,5) {
+    qwtAddLibrary($${QWT_OUT_ROOT}/lib,qwt-qt6)
+}
+else {
+    qwtAddLibrary($${QWT_OUT_ROOT}/lib,qwt-qt5)
+}