--- CMakeLists.txt.orig	2021-01-11 09:41:28 UTC
+++ CMakeLists.txt
@@ -64,6 +64,7 @@ find_package(Qt5Core             REQUIRED)
 find_package(Qt5Concurrent       REQUIRED)
 find_package(Qt5Widgets          REQUIRED)
 find_package(Qt5Gui              REQUIRED)
+if (WITH_HELPBROWSER)
 # QtWebEngine is preferred web engine because QtWebKit is deprecated since Qt 5.5:
 # https://wiki.qt.io/New-Features-in-Qt-5.5#Deprecated_Functionality. Unfortunately,
 # some Qt distributions still provide QtWebKit instead of QtWebEngine. So first we
@@ -75,6 +76,8 @@ else()
     find_package(Qt5WebKit           REQUIRED)
     find_package(Qt5WebKitWidgets    REQUIRED)
     add_definitions(-DUSE_DEPRECATED_QTWEBKIT)
+endif()
+    add_definitions(-DWITH_HELPBROWSER)
 endif()
 find_package(Qt5Xml              REQUIRED)
 find_package(Qt5Sql              REQUIRED)