diff --git a/gcc/cpphash.c b/gcc/cpphash.c
index fe7cbbf15f1..2ca007c417c 100644
--- a/gcc/cpphash.c
+++ b/gcc/cpphash.c
@@ -31,6 +31,11 @@ Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 #define NULL 0
 #endif
 
+#ifndef __STDC__
+#define const
+#define volatile
+#endif
+
 /*
  * return hash function on name.  must be compatible with the one
  * computed a step at a time, elsewhere