diff --git a/core/host/host_task.h b/core/host/host_task.h
index e4e0712ea2..cc9b4ae9ea 100644
--- a/core/host/host_task.h
+++ b/core/host/host_task.h
@@ -23,4 +23,15 @@ pthread_t task_get_thread(task_id_t tskid);
  */
 task_id_t task_get_running(void);
 
+/**
+ * Initializes the interrupt semaphore and associates a signal handler with
+ * SIGNAL_INTERRUPT.
+ */
+void task_register_interrupt(void);
+
+/**
+ * Returns the process ID of the calling process.
+ */
+pid_t getpid(void);
+
 #endif  /* __CROS_EC_HOST_TASK_H */
diff --git a/core/host/main.c b/core/host/main.c
index fbb28d9127..64976c0c89 100644
--- a/core/host/main.c
+++ b/core/host/main.c
@@ -8,6 +8,7 @@
 #include "console.h"
 #include "flash.h"
 #include "hooks.h"
+#include "host_task.h"
 #include "keyboard_scan.h"
 #include "stack_trace.h"
 #include "system.h"
@@ -31,6 +32,12 @@ int main(int argc, char **argv)
 {
 	__prog_name = argv[0];
 
+	/*
+	 * In order to properly service IRQs before task switching is enabled,
+	 * we must set up our signal handler for the main thread.
+	 */
+	task_register_interrupt();
+
 	task_register_tracedump();
 
 	register_test_end_hook();
diff --git a/core/host/task.c b/core/host/task.c
index 28c0cb0297..9c2e650c84 100644
--- a/core/host/task.c
+++ b/core/host/task.c
@@ -125,7 +125,7 @@ static void _task_execute_isr(int sig)
 	in_interrupt = 0;
 }
 
-static void task_register_interrupt(void)
+void task_register_interrupt(void)
 {
 	sem_init(&interrupt_sem, 0, 0);
 	signal(SIGNAL_INTERRUPT, _task_execute_isr);
@@ -133,6 +133,7 @@ static void task_register_interrupt(void)
 
 void task_trigger_test_interrupt(void (*isr)(void))
 {
+	pid_t main_pid;
 	pthread_mutex_lock(&interrupt_lock);
 	if (interrupt_disabled) {
 		pthread_mutex_unlock(&interrupt_lock);
@@ -141,7 +142,12 @@ void task_trigger_test_interrupt(void (*isr)(void))
 
 	/* Suspend current task and excute ISR */
 	pending_isr = isr;
-	pthread_kill(tasks[running_task_id].thread, SIGNAL_INTERRUPT);
+	if (task_started) {
+		pthread_kill(tasks[running_task_id].thread, SIGNAL_INTERRUPT);
+	} else {
+		main_pid = getpid();
+		kill(main_pid, SIGNAL_INTERRUPT);
+	}
 
 	/* Wait for ISR to complete */
 	sem_wait(&interrupt_sem);
@@ -416,8 +422,6 @@ int task_start(void)
 {
 	int i = TASK_ID_HOOKS;
 
-	task_register_interrupt();
-
 	pthread_mutex_init(&run_lock, NULL);
 	pthread_mutex_init(&interrupt_lock, NULL);
 	pthread_cond_init(&scheduler_cond, NULL);