diff --git a/gcc/config/m68k/xm-plexus.h b/gcc/config/m68k/xm-plexus.h
new file mode 100644
index 00000000000..9eea7dea332
--- /dev/null
+++ b/gcc/config/m68k/xm-plexus.h
@@ -0,0 +1,20 @@
+/* Host environment for 68000's running System V.  */
+
+#include "xm-m68k.h"
+
+#define USG
+#define bcopy(a,b,c) memcpy (b,a,c)
+#define bzero(a,b) memset (a,0,b)
+#define bcmp(a,b,c) memcmp (a,b,c)
+
+#define rindex strrchr
+#define index strchr
+
+#ifndef __GNUC__
+#define USE_C_ALLOCA
+#endif
+
+#ifndef _SIZE_T_
+typedef int size_t;
+#define _SIZE_T_
+#endif