diff --git a/drivers/staging/greybus/protocol.c b/drivers/staging/greybus/protocol.c
index 52944ecea075..e0bcd4bc28a5 100644
--- a/drivers/staging/greybus/protocol.c
+++ b/drivers/staging/greybus/protocol.c
@@ -13,7 +13,7 @@ static DEFINE_SPINLOCK(gb_protocols_lock);
 static LIST_HEAD(gb_protocols);
 
 /* Caller must hold gb_protocols_lock */
-struct gb_protocol *_gb_protocol_find(u8 id)
+static struct gb_protocol *_gb_protocol_find(u8 id)
 {
 	struct gb_protocol *protocol;