diff --git a/configs/efi-x86_app64_defconfig b/configs/efi-x86_app64_defconfig
index 0fc358d..46a1900 100644
--- a/configs/efi-x86_app64_defconfig
+++ b/configs/efi-x86_app64_defconfig
@@ -2,7 +2,7 @@
 CONFIG_NR_DRAM_BANKS=8
 CONFIG_ENV_SIZE=0x1000
 CONFIG_DEFAULT_DEVICE_TREE="efi-x86_app"
-CONFIG_DEBUG_UART_BASE=0
+CONFIG_DEBUG_UART_BASE=0x0
 CONFIG_DEBUG_UART_CLOCK=0
 CONFIG_X86_RUN_64BIT=y
 CONFIG_VENDOR_EFI=y