diff --git a/drivers/clk/renesas/r8a779a0-cpg-mssr.c b/drivers/clk/renesas/r8a779a0-cpg-mssr.c
index 17ebbac7ddfb..7e25b3b8945b 100644
--- a/drivers/clk/renesas/r8a779a0-cpg-mssr.c
+++ b/drivers/clk/renesas/r8a779a0-cpg-mssr.c
@@ -153,7 +153,7 @@ static const struct rcar_r8a779a0_cpg_pll_config *cpg_pll_config __initdata;
 static unsigned int cpg_clk_extalr __initdata;
 static u32 cpg_mode __initdata;
 
-struct clk * __init rcar_r8a779a0_cpg_clk_register(struct device *dev,
+static struct clk * __init rcar_r8a779a0_cpg_clk_register(struct device *dev,
 	const struct cpg_core_clk *core, const struct cpg_mssr_info *info,
 	struct clk **clks, void __iomem *base,
 	struct raw_notifier_head *notifiers)