diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index d6170adaf5..5e66304e2b 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -130,6 +130,23 @@ void os_exit(int exit_code)
 	exit(exit_code);
 }
 
+unsigned int os_alarm(unsigned int seconds)
+{
+	return alarm(seconds);
+}
+
+void os_set_alarm_handler(void (*handler)(int))
+{
+	if (!handler)
+		handler = SIG_DFL;
+	signal(SIGALRM, handler);
+}
+
+void os_raise_sigalrm(void)
+{
+	raise(SIGALRM);
+}
+
 int os_write_file(const char *fname, const void *buf, int size)
 {
 	int fd;
diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index 48a7fd2bc2..0475672968 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -56,6 +56,7 @@ CONFIG_CMD_REMOTEPROC=y
 CONFIG_CMD_SPI=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_CAT=y
+CONFIG_CMD_WDT=y
 CONFIG_BOOTP_DNS2=y
 CONFIG_CMD_TFTPPUT=y
 CONFIG_CMD_TFTPSRV=y
@@ -238,6 +239,7 @@ CONFIG_SPLASH_SCREEN_ALIGN=y
 CONFIG_WDT=y
 CONFIG_WDT_GPIO=y
 CONFIG_WDT_SANDBOX=y
+CONFIG_WDT_ALARM_SANDBOX=y
 CONFIG_FS_CBFS=y
 CONFIG_FS_CRAMFS=y
 CONFIG_CMD_DHRYSTONE=y
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index e18e666f12..34e90674ee 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -80,6 +80,7 @@ CONFIG_CMD_REMOTEPROC=y
 CONFIG_CMD_SPI=y
 CONFIG_CMD_TEMPERATURE=y
 CONFIG_CMD_USB=y
+CONFIG_CMD_WDT=y
 CONFIG_CMD_AXI=y
 CONFIG_CMD_CAT=y
 CONFIG_CMD_SETEXPR_FMT=y
@@ -314,6 +315,7 @@ CONFIG_W1_EEPROM_SANDBOX=y
 CONFIG_WDT=y
 CONFIG_WDT_GPIO=y
 CONFIG_WDT_SANDBOX=y
+CONFIG_WDT_ALARM_SANDBOX=y
 CONFIG_FS_CBFS=y
 CONFIG_FS_CRAMFS=y
 CONFIG_ADDR_MAP=y
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index e55deaf906..29e375e117 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -281,6 +281,14 @@ config WDT_SANDBOX
 	  can be probed and supports all of the methods of WDT, but does not
 	  really do anything.
 
+config WDT_ALARM_SANDBOX
+	bool "Enable SIGALRM-based Watchdog Timer support for Sandbox"
+	depends on SANDBOX && WDT
+	help
+	  Enable support for a SIGALRM-based watchdog timer in Sandbox. This is
+	  a watchdog device based on the host OS' alarm() function, which will
+	  kill the sandbox with SIGALRM unless properly maintained.
+
 config WDT_SBSA
 	bool "SBSA watchdog timer support"
 	depends on WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 0e2f582a5f..446d961d7d 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_DESIGNWARE_WATCHDOG) += designware_wdt.o
 obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o
 obj-$(CONFIG_$(SPL_TPL_)WDT) += wdt-uclass.o
 obj-$(CONFIG_WDT_SANDBOX) += sandbox_wdt.o
+obj-$(CONFIG_WDT_ALARM_SANDBOX) += sandbox_alarm-wdt.o
 obj-$(CONFIG_WDT_APPLE) += apple_wdt.o
 obj-$(CONFIG_WDT_ARMADA_37XX) += armada-37xx-wdt.o
 obj-$(CONFIG_WDT_ASPEED) += ast_wdt.o
diff --git a/drivers/watchdog/sandbox_alarm-wdt.c b/drivers/watchdog/sandbox_alarm-wdt.c
new file mode 100644
index 0000000000..71bb5d924e
--- /dev/null
+++ b/drivers/watchdog/sandbox_alarm-wdt.c
@@ -0,0 +1,79 @@
+#include <common.h>
+#include <dm.h>
+#include <os.h>
+#include <wdt.h>
+
+struct alarm_wdt_priv {
+	unsigned int timeout_sec;
+};
+
+static void alarm_handler(int sig)
+{
+	const char *msg = "!!! ALARM !!!\n";
+
+	os_write(2, msg, strlen(msg));
+	os_fd_restore();
+	os_set_alarm_handler(NULL);
+	os_raise_sigalrm();
+}
+
+static int alarm_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+	struct alarm_wdt_priv *priv = dev_get_priv(dev);
+	unsigned int sec;
+
+	timeout = DIV_ROUND_UP(timeout, 1000);
+	sec = min_t(u64, UINT_MAX, timeout);
+	priv->timeout_sec = sec;
+
+	os_alarm(0);
+	os_set_alarm_handler(alarm_handler);
+	os_alarm(sec);
+
+	return 0;
+}
+
+static int alarm_wdt_stop(struct udevice *dev)
+{
+	os_alarm(0);
+	os_set_alarm_handler(NULL);
+
+	return 0;
+}
+
+static int alarm_wdt_reset(struct udevice *dev)
+{
+	struct alarm_wdt_priv *priv = dev_get_priv(dev);
+
+	os_alarm(priv->timeout_sec);
+
+	return 0;
+}
+
+static int alarm_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+	alarm_handler(0);
+
+	return 0;
+}
+
+
+static const struct wdt_ops alarm_wdt_ops = {
+	.start = alarm_wdt_start,
+	.reset = alarm_wdt_reset,
+	.stop = alarm_wdt_stop,
+	.expire_now = alarm_wdt_expire_now,
+};
+
+static const struct udevice_id alarm_wdt_ids[] = {
+	{ .compatible = "sandbox,alarm-wdt" },
+	{}
+};
+
+U_BOOT_DRIVER(alarm_wdt_sandbox) = {
+	.name = "alarm_wdt_sandbox",
+	.id = UCLASS_WDT,
+	.of_match = alarm_wdt_ids,
+	.ops = &alarm_wdt_ops,
+	.priv_auto = sizeof(struct alarm_wdt_priv),
+};
diff --git a/include/os.h b/include/os.h
index 5b353ae9d9..54874f5e0e 100644
--- a/include/os.h
+++ b/include/os.h
@@ -108,6 +108,23 @@ int os_unlink(const char *pathname);
  */
 void os_exit(int exit_code) __attribute__((noreturn));
 
+/**
+ * os_alarm() - access to the OS alarm() system call
+ */
+unsigned int os_alarm(unsigned int seconds);
+
+/**
+ * os_set_alarm_handler() - set handler for SIGALRM
+ *
+ * @handler:   The handler function. Pass NULL for SIG_DFL.
+ */
+void os_set_alarm_handler(void (*handler)(int));
+
+/**
+ * os_raise_sigalrm() - do raise(SIGALRM)
+ */
+void os_raise_sigalrm(void);
+
 /**
  * os_tty_raw() - put tty into raw mode to mimic serial console better
  *