Backport of https://github.com/zealdocs/zeal/pull/1644
Done manually because CMakeLists.txt has CRLF line endings in release tarball.
--- a/src/app/CMakeLists.txt
+++ b/src/app/CMakeLists.txt
@@ -1,4 +1,4 @@
-find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Widgets REQUIRED)
+find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Concurrent WebEngineWidgets Widgets REQUIRED)
 if (Qt${QT_VERSION_MAJOR}Widgets_VERSION VERSION_LESS QT_MINIMUM_VERSION)
     message(FATAL_ERROR "Qt version >= ${QT_MINIMUM_VERSION} is required.")
 endif()