diff --git a/drivers/serial/serial_s5p.c b/drivers/serial/serial_s5p.c
index 7aeb8c0..fe52580 100644
--- a/drivers/serial/serial_s5p.c
+++ b/drivers/serial/serial_s5p.c
@@ -118,7 +118,7 @@
 
 #if IS_ENABLED(CONFIG_CLK_EXYNOS) || IS_ENABLED(CONFIG_ARCH_APPLE)
 	struct clk clk;
-	u32 ret;
+	int ret;
 
 	ret = clk_get_by_index(dev, 1, &clk);
 	if (ret < 0)