Keypad.h and ESP8266WiFi.h not cooperating

[jendam99]

Hello,
I am currently trying to use ESP-now to connect a keypad unit and reciever unit, but as soon as I import both libraries into the same sketch and try to compile it (in Arduino IDE), multiple error messages are shown.
Some of them complain about expansion of macros (like for example: "wl_definitions.h:73:3: note: in expansion of macro 'CLOSED' CLOSED = 0,")
Other say "... ESP8266WiFi.h:29:1: error: expected declaration before '}' token }" mentioning all different ESP8266 libraries.
Do you have any idea, where is the problem and how to solve it?
Thank you in advance.