diff --git a/src/soc/mediatek/mt8188/soc.c b/src/soc/mediatek/mt8188/soc.c
index 35071d50f1..e7124ba14e 100644
--- a/src/soc/mediatek/mt8188/soc.c
+++ b/src/soc/mediatek/mt8188/soc.c
@@ -15,7 +15,7 @@
 #include <symbols.h>
 
 #define OPTEE_ADDRESS		0x43000000
-#define OPTEE_SIZE		(80 * MiB)
+#define OPTEE_SIZE		(70 * MiB)
 
 void bootmem_platform_add_ranges(void)
 {