diff --git a/drivers/clk/rockchip/clk-rk1808.c b/drivers/clk/rockchip/clk-rk1808.c
index 7d27b5fb313f..c810587e7490 100644
--- a/drivers/clk/rockchip/clk-rk1808.c
+++ b/drivers/clk/rockchip/clk-rk1808.c
@@ -1066,7 +1066,7 @@ static struct rockchip_clk_branch rk1808_clk_branches[] __initdata = {
 
 	/* PD_PMU */
 
-	COMPOSITE_FRACMUX(0, "clk_rtc32k_frac", "xin24m", CLK_IGNORE_UNUSED,
+	COMPOSITE_FRACMUX(SCLK_RTC32K_FRAC, "clk_rtc32k_frac", "xin24m", CLK_IGNORE_UNUSED,
 			RK1808_PMU_CLKSEL_CON(1), 0,
 			RK1808_PMU_CLKGATE_CON(0), 13, GFLAGS,
 			&rk1808_rtc32k_pmu_fracmux, 0),
diff --git a/include/dt-bindings/clock/rk1808-cru.h b/include/dt-bindings/clock/rk1808-cru.h
index 3378b36401bc..3dd5c76d5295 100644
--- a/include/dt-bindings/clock/rk1808-cru.h
+++ b/include/dt-bindings/clock/rk1808-cru.h
@@ -110,6 +110,7 @@
 #define SCLK_USBPHY_REF		109
 #define SCLK_MIPIDSIPHY_REF	110
 #define SCLK_PCIEPHY_REF	111
+#define SCLK_RTC32K_FRAC	112
 
 /* aclk gates */
 #define ACLK_GIC_PRE		145