diff --git a/src/unexnext.c b/src/unexnext.c
index 1cf41ca05a1..e250245088c 100644
--- a/src/unexnext.c
+++ b/src/unexnext.c
@@ -30,7 +30,8 @@ Boston, MA 02111-1307, USA.  */
 #include <mach-o/reloc.h>
 #include <sys/file.h>
 #include <sys/stat.h>
-#include <libc.h>
+#include <unistd.h>
+/* Instead of unistd.h, this used to include libc.h.  */
 
 
 int malloc_cookie;