Fix missing prototype warning
diff --git a/src/SDL_hints.c b/src/SDL_hints.c
index 0337def..2d43133 100644
--- a/src/SDL_hints.c
+++ b/src/SDL_hints.c
@@ -22,6 +22,7 @@
#include "SDL_hints.h"
#include "SDL_error.h"
+#include "SDL_hints_c.h"
/* Assuming there aren't many hints set and they aren't being queried in