diff --git a/gcc/config/i860/mach.h b/gcc/config/i860/mach.h
new file mode 100644
index 00000000000..3f752c6f9d6
--- /dev/null
+++ b/gcc/config/i860/mach.h
@@ -0,0 +1,12 @@
+/* Configuration for an i860 running Mach as the target machine.  */
+
+#include "i860.h"
+
+#undef TARGET_VERSION
+#define TARGET_VERSION fprintf (stderr, " (i860 Mach3.x)");
+
+#undef CPP_PREDEFINES
+#define CPP_PREDEFINES "-Dunix -Di860 -DMACH"
+
+/* Specify extra dir to search for include files.  */
+#define SYSTEM_INCLUDE_DIR "/usr/mach/include"