--- a/include/libbb.h
+++ b/include/libbb.h
@@ -83,7 +83,10 @@
 extern char **environ;
 
 /* Set the group set for the current user to GROUPS (N of them).  */
+#if !defined(__APPLE__)
 int setgroups(size_t n, const gid_t *groups);
+#endif
+
 #if defined(__GLIBC__) && __GLIBC__ < 2
 int vdprintf(int d, const char *format, va_list ap);
 #endif