diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index b6db79a00602b22016f65a046946dc733531797d..35dbd63c2f49b03b87866b870b0700aebf333867 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -169,7 +169,7 @@ static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
  * fractional divider must set that denominator is 20 times larger than
  * numerator to generate precise clock frequency.
  */
-void rockchip_fractional_approximation(struct clk_hw *hw,
+static void rockchip_fractional_approximation(struct clk_hw *hw,
 		unsigned long rate, unsigned long *parent_rate,
 		unsigned long *m, unsigned long *n)
 {