cf.: https://stackoverflow.com/questions/39281740/why-are-qt-signals-not-const when you want to emit a signal from a const method, the signal has to be const. so there is a valid reason for when to make a signal const
This has been discussed previously, and there's two schools of thought: The purists say: - signals are emitted to express that state has changed - const methods don't change state - so don't emit from const methods The rebels say: - Yeah, but I'm keeping state also in some global variables as I don't care about OOP so much - And I can change these global variables from any const method So the only solution is for you to disable the check