Compiler-Warning: ISO C++11 requires whitespace after the macro name

[DonNagual]

I am currently learning to work with crowcpp

here is my code:

#include "crow.h"

int main()
{
    crow::SimpleApp app; // define your crow application

    // define your endpoint at the root directory
    CROW_ROUTE ( app, "/" ) ( [ ] ( ) {
        return "Hello world!";
    });

    // set the port, set the app to run on multiple threads, and run the app
    app.bindaddr("127.0.0.1").port(8080).multithreaded().run();
}

Even though building works, I get a warning. Since I didn't write any macros, this warning probably comes from crow itself.
Is this a problem?

Here is the build-output

arkadiusz@arkadows:~/Praktika_Dev/ai-internal_minimal-crow-websocket_sw/build$ cmake ..
-- The CXX compiler identification is GNU 11.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found asio: /usr/include
-- Configuring done
-- Generating done
-- Build files have been written to: /home/arkadiusz/Praktika_Dev/ai-internal_minimal-crow-websocket_sw/build
arkadiusz@arkadows:~/Praktika_Dev/ai-internal_minimal-crow-websocket_sw/build$ cmake --build .
[ 50%] Building CXX object CMakeFiles/server.dir/server.cpp.o
<command-line>: warning: ISO C++11 requires whitespace after the macro name
[100%] Linking CXX executable server
[100%] Built target server