diff --git a/gcc/config/m88k/luna.h b/gcc/config/m88k/luna.h
index bd4d254e4b43..4531646ce961 100644
--- a/gcc/config/m88k/luna.h
+++ b/gcc/config/m88k/luna.h
@@ -26,6 +26,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #endif
 #define DBX_DEBUGGING_INFO
 
+#include "aoutos.h"
 #include "m88k.h"
 
 /* Identify the compiler.  */