diff -rupN --no-dereference qwt-6.1.4/qwtfunctions.pri qwt-6.1.4-new/qwtfunctions.pri
--- qwt-6.1.4/qwtfunctions.pri	2019-01-02 17:21:31.552467404 +0100
+++ qwt-6.1.4-new/qwtfunctions.pri	2020-01-06 17:17:19.882623791 +0100
@@ -12,7 +12,12 @@
 defineReplace(qwtLibraryTarget) {
 
     unset(LIBRARY_NAME)
+
+    greaterThan(QT_MAJOR_VERSION, 4) {
+    LIBRARY_NAME = $${1}-qt$${QT_MAJOR_VERSION}
+    } else {
     LIBRARY_NAME = $$1
+    }
 
     mac:contains(QWT_CONFIG, QwtFramework) {
 
@@ -36,7 +41,11 @@ defineReplace(qwtLibraryTarget) {
 defineTest(qwtAddLibrary) {
 
     LIB_PATH = $$1
+    greaterThan(QT_MAJOR_VERSION, 4) {
+    LIB_NAME = $${2}-qt$${QT_MAJOR_VERSION}
+    } else {
     LIB_NAME = $$2
+    }
 
     mac:contains(QWT_CONFIG, QwtFramework) {