Use the non-overlayed libbsd headers when we need our own definitions
diff --git a/include/bsd/err.h b/include/bsd/err.h
index b465c1b..12fd051 100644
--- a/include/bsd/err.h
+++ b/include/bsd/err.h
@@ -34,7 +34,11 @@
#ifndef LIBBSD_ERR_H
#define LIBBSD_ERR_H
+#ifdef LIBBSD_OVERLAY
#include <sys/cdefs.h>
+#else
+#include <bsd/sys/cdefs.h>
+#endif
#include <stdarg.h>
diff --git a/include/bsd/unistd.h b/include/bsd/unistd.h
index 78a4525..1f9c5f8 100644
--- a/include/bsd/unistd.h
+++ b/include/bsd/unistd.h
@@ -34,7 +34,11 @@
#ifndef LIBBSD_UNISTD_H
#define LIBBSD_UNISTD_H
+#ifdef LIBBSD_OVERLAY
#include <sys/cdefs.h>
+#else
+#include <bsd/sys/cdefs.h>
+#endif
#include <sys/stat.h>
#ifndef S_ISTXT