diff --git a/targets/TARGET_Realtek/TARGET_AMEBA/flash_ext.h b/targets/TARGET_Realtek/TARGET_AMEBA/flash_ext.h
index 6ad5c799da..b2d287bf61 100644
--- a/targets/TARGET_Realtek/TARGET_AMEBA/flash_ext.h
+++ b/targets/TARGET_Realtek/TARGET_AMEBA/flash_ext.h
@@ -24,7 +24,7 @@ extern "C" {
 #endif
 
 #define FLASH_PAGE_SIZE 256
-#define FLASH_SIZE        0x100000
+#define FLASH_SIZE        0x200000
 #define FLASH_OFS_START   0x0
 #define FLASH_OFS_END     (FLASH_OFS_START + FLASH_SIZE)