diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@
 option(PHONON_NO_CAPTURE "Disable the capture capabilities")
 option(PHONON_NO_DBUS "Deactivate DBus support (used to expose AudioOutputs and for deprecated runtime backend switching)" OFF)
 
-option(PHONON_BUILD_PHONON4QT5 "Build Phonon 4 transitional library for Qt5 (API compatible with regular Phonon4)" OFF)
+option(PHONON_BUILD_PHONON4QT5 "Build Phonon 4 transitional library for Qt5 (API compatible with regular Phonon4)" ON)
 
 # The following variables directly influence the library's soname version.
 # It is highly advised to think twice before changing those.