diff --git a/lib/libc/Makefile b/lib/libc/Makefile
index 674986a7e065..03231a1a9f2c 100644
--- a/lib/libc/Makefile
+++ b/lib/libc/Makefile
@@ -26,6 +26,7 @@ LIBC_ARCH=${MACHINE_CPUARCH}
 # To include legacy CSRG SCCS ID strings, remove -DNO__SCCSID from CFLAGS.
 # To include RCS ID strings from other BSD projects, remove -DNO__RCSID from CFLAGS.
 CFLAGS+=-DNO__SCCSID -DNO__RCSID
+CFLAGS+=-D__MACH__ -D__RAVYNOS__
 
 LIB=c
 SHLIB_MAJOR= 7
diff --git a/lib/libsys/Makefile b/lib/libsys/Makefile
index b4c0e91e860c..73eca78029b3 100644
--- a/lib/libsys/Makefile
+++ b/lib/libsys/Makefile
@@ -28,6 +28,7 @@ INCS=	libsys.h _libsys.h
 CFLAGS+=-I${LIBSYS_SRCTOP}/include -I${LIBC_SRCTOP}/include
 CFLAGS+=-I${LIBSYS_SRCTOP}/${LIBC_ARCH}
 CFLAGS+=-I${LIBC_SRCTOP}/${LIBC_ARCH}
+CFLAGS+=-D__MACH__ -D__RAVYNOS__
 
 .PATH: ${LIBC_SRCTOP}/string
 SRCS+=	memcpy.c memset.c strlcpy.c