diff --git a/vms/writemain.pl b/vms/writemain.pl
index cd4c534ad38..eb059f810a7 100644
--- a/vms/writemain.pl
+++ b/vms/writemain.pl
@@ -36,6 +36,7 @@
 static void
 xs_init()
 {
+    dXSUB_SYS;
 EOH
 
 if (@ARGV) {
diff --git a/writemain.SH b/writemain.SH
index e53af7d7de7..4884a387a17 100644
--- a/writemain.SH
+++ b/writemain.SH
@@ -69,6 +69,7 @@ cat << 'EOP'
 static void
 xs_init()
 {
+  dXSUB_SYS;
 EOP
 
 if test X"$args" != "X" ; then