False positive on Misra 10.3 for bools

[Andreas]

For my c11 project I get false positives on MISRA 10.3 (The value of an expression shall not be assigned to an object with a narrower essential type or of a different essential type category) when assigning true or false to a boolean variable.
I suppose this is because stdbool.h defines:

#define true 1
#define false 0

Which makes true and false essentially signed integers.

Here some example code:

#include <stdbool.h>

bool dummy_func(int val)
{
  bool my_bool;
  if (val > 10)
  {
    my_bool = true;   // Triggers warning for MISRA 10.3
  }
  else
  {
    my_bool = false;   // Triggers warning for MISRA 10.3
  }
  return my_bool;
}

I am running cppcheck from the GUI and I cannot find a setting for which c standard I use - in case that is the problem.

[Andreas]

After writing the above I did find the setting for C-standard in the GUI. However, the problem still remains.