diff --git a/vl.c b/vl.c
index 743e613..9919120 100644
--- a/vl.c
+++ b/vl.c
@@ -7359,7 +7359,7 @@
 /***********************************************************/
 /* machine registration */
 
-QEMUMachine *first_machine = NULL;
+static QEMUMachine *first_machine = NULL;
 
 int qemu_register_machine(QEMUMachine *m)
 {