diff --git a/configs/rock960-rk3399_defconfig b/configs/rock960-rk3399_defconfig
index 17311e6..cb5a35f 100644
--- a/configs/rock960-rk3399_defconfig
+++ b/configs/rock960-rk3399_defconfig
@@ -45,6 +45,7 @@
 CONFIG_MMC_DW_ROCKCHIP=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_ROCKCHIP=y
+CONFIG_SF_DEFAULT_SPEED=20000000
 CONFIG_PINCTRL=y
 CONFIG_SPL_PINCTRL=y
 CONFIG_DM_PMIC=y