diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index f82dc9c..2066d0a 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -7,6 +7,7 @@
 CONFIG_BOOTSTAGE_STASH_ADDR=0x0
 CONFIG_DEFAULT_DEVICE_TREE="sandbox64"
 CONFIG_SANDBOX64=y
+CONFIG_DEBUG_UART=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_FIT_SIGNATURE=y
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index edca7f1..efd99a9 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -5,6 +5,7 @@
 CONFIG_ENV_SIZE=0x2000
 CONFIG_BOOTSTAGE_STASH_ADDR=0x0
 CONFIG_DEFAULT_DEVICE_TREE="sandbox"
+CONFIG_DEBUG_UART=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_FIT_SIGNATURE=y
diff --git a/configs/sandbox_spl_defconfig b/configs/sandbox_spl_defconfig
index 479f022..d193b18 100644
--- a/configs/sandbox_spl_defconfig
+++ b/configs/sandbox_spl_defconfig
@@ -11,6 +11,7 @@
 CONFIG_BOOTSTAGE_STASH_ADDR=0x0
 CONFIG_DEFAULT_DEVICE_TREE="sandbox"
 CONFIG_SANDBOX_SPL=y
+CONFIG_DEBUG_UART=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_FIT_SIGNATURE=y