diff --git a/mach/proto/cg/subr.c b/mach/proto/cg/subr.c
index d174e3f16..a3801ffca 100644
--- a/mach/proto/cg/subr.c
+++ b/mach/proto/cg/subr.c
@@ -30,7 +30,7 @@ static char rcsid[] = "$Header$";
  * Author: Hans van Staveren
  */
 
-string myalloc();
+extern string myalloc();
 unsigned codegen();
 
 match(tp,tep,optexp) register token_p tp; register set_p tep; {