diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 370b9dd7a2786841f3180d732321c99416030559..3a3a47f60d2894a1f0c33c251cdb741f19879cdf 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -897,7 +897,7 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 /* this function examines buffers to see if they contain data that
  * indicate that the buffer is part of an erased region of flash.
  */
-bool is_erased(uint8_t *buf, int len)
+static bool is_erased(uint8_t *buf, int len)
 {
 	int i = 0;
 	for (i = 0; i < len; i++)