diff --git a/mkproto.awk b/mkproto.awk
index a64d132e..bd2e927b 100644
--- a/mkproto.awk
+++ b/mkproto.awk
@@ -36,5 +36,5 @@ inheader {
 
 END {
     if (old_protos != protos) print protos > "proto.h"
-    printf "" > "proto.h-tstamp"
+    system("touch proto.h-tstamp")
 }