--- gcc/config/m68k/plexus.h	2018/04/24 18:10:24	1.1
+++ gcc/config/m68k/plexus.h	2018/04/24 18:14:31	1.1.1.2
@@ -48,7 +48,7 @@ the Free Software Foundation, 675 Mass A
 #define LONG_DOUBLE_TYPE_SIZE 64
 
 #define CPP_SPEC "%{m68881:-D__HAVE_68881__}"
-#define CPP_PREDEFINES "-Dm68 -Dunix -Dplexus"
+#define CPP_PREDEFINES "-Dm68 -Dunix -Dplexus -Asystem(unix)  -Acpu(m68k) -Amachine(m68k)"
 
 #if TARGET_DEFAULT & 01
 #define ASM_SPEC\