How to get the updated screen resolution?

Let’s say I do the following:

-set my screen resolution in Windows to 1920x1080
-start my program
-call SDL_GetCurrentDisplayMode() or SDL_GetDisplayBounds() which gives me 1920x1080
-change my screen resolution in Windows to 1440x900
-call SDL_GetCurrentDisplayMode() or SDL_GetDisplayBounds() which STILL gives me 1920x1080

It seems like these functions simply return some stored values without updating. What can I do in order to get up-to-date values?