diff --git a/drivers/macintosh/windfarm_pm121.c b/drivers/macintosh/windfarm_pm121.c
index ab467b9c31be..ba1ec6fc11d2 100644
--- a/drivers/macintosh/windfarm_pm121.c
+++ b/drivers/macintosh/windfarm_pm121.c
@@ -433,7 +433,7 @@ struct pm121_sys_state {
 	struct wf_pid_state	pid;
 };
 
-struct pm121_sys_state *pm121_sys_state[N_LOOPS] = {};
+static struct pm121_sys_state *pm121_sys_state[N_LOOPS] = {};
 
 /*
  * ****** CPU Fans Control Loop ******