diff --git a/plat/mediatek/mt8173/drivers/spm/spm.c b/plat/mediatek/mt8173/drivers/spm/spm.c
index 280192568..45defd8aa 100644
--- a/plat/mediatek/mt8173/drivers/spm/spm.c
+++ b/plat/mediatek/mt8173/drivers/spm/spm.c
@@ -386,6 +386,8 @@ void spm_boot_init(void)
 {
 	/* Only CPU0 is online during boot, initialize cpu online reserve bit */
 	mmio_write_32(SPM_PCM_RESERVE, 0xFE);
+	mmio_clrbits_32(AP_PLL_CON3, 0xFFFFF);
+	mmio_clrbits_32(AP_PLL_CON4, 0xF);
 	spm_lock_init();
 	spm_register_init();
 }
diff --git a/plat/mediatek/mt8173/drivers/spm/spm.h b/plat/mediatek/mt8173/drivers/spm/spm.h
index f1e767457..4e78c7277 100644
--- a/plat/mediatek/mt8173/drivers/spm/spm.h
+++ b/plat/mediatek/mt8173/drivers/spm/spm.h
@@ -129,6 +129,9 @@
 #define SPM_SLEEP_CA15_WFI2_EN			(SPM_BASE + 0xf18)
 #define SPM_SLEEP_CA15_WFI3_EN			(SPM_BASE + 0xf1c)
 
+#define AP_PLL_CON3		0x1020900c
+#define AP_PLL_CON4		0x10209010
+
 #define SPM_PROJECT_CODE	0xb16
 
 #define SPM_REGWR_EN		(1U << 0)