diff --git a/target-sparc/helper.c b/target-sparc/helper.c
index 6aca8fd..f222e3a 100644
--- a/target-sparc/helper.c
+++ b/target-sparc/helper.c
@@ -38,7 +38,7 @@
 
 /* thread support */
 
-spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;
+static spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;
 
 void cpu_lock(void)
 {