diff --git a/nestegg/halloc/src/macros.h b/nestegg/halloc/src/macros.h index c36b516ee..1f84bc277 100644 --- a/nestegg/halloc/src/macros.h +++ b/nestegg/halloc/src/macros.h @@ -20,7 +20,7 @@ /* restore pointer to the structure by a pointer to its field */ -#define structof(p,t,f) ((t*)(- offsetof(t,f) + (char*)(p))) +#define structof(p,t,f) ((t*)(- (ptrdiff_t) offsetof(t,f) + (char*)(p))) /* * redefine for the target compiler