diff --git a/killer/CMakeLists.txt b/killer/CMakeLists.txt
index 9c4c0ab41d..9e867ecd4e 100644
--- a/killer/CMakeLists.txt
+++ b/killer/CMakeLists.txt
@@ -4,7 +4,6 @@ set(kwin_killer_helper_SRCS killer.cpp )
 
 
 add_executable(kwin_killer_helper ${kwin_killer_helper_SRCS})
-set_target_properties(kwin_killer_helper PROPERTIES COMPILE_FLAGS ${Qt5Widgets_EXECUTABLE_COMPILE_FLAGS})
 
 target_link_libraries(kwin_killer_helper
     Qt5::Widgets