diff --git a/arch/um/include/linux/time-internal.h b/arch/um/include/linux/time-internal.h
index f3b03d39a854387e4b6544ff1297bedaa2b0f53a..68e45e950137c1539cb8fcff1cf9351a9e179051 100644
--- a/arch/um/include/linux/time-internal.h
+++ b/arch/um/include/linux/time-internal.h
@@ -28,7 +28,7 @@ struct time_travel_event {
 
 extern enum time_travel_mode time_travel_mode;
 
-void time_travel_sleep(unsigned long long duration);
+void time_travel_sleep(void);
 
 static inline void
 time_travel_set_event_fn(struct time_travel_event *e,
@@ -60,7 +60,7 @@ struct time_travel_event {
 
 #define time_travel_mode TT_MODE_OFF
 
-static inline void time_travel_sleep(unsigned long long duration)
+static inline void time_travel_sleep(void)
 {
 }
 
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index e2bb7e488d5995807175eec75666c396de286347..0f7fb8bad728c5438e2079a8cebd4fef786f81e9 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -256,7 +256,7 @@ extern void os_warn(const char *fmt, ...)
 	__attribute__ ((format (printf, 1, 2)));
 
 /* time.c */
-extern void os_idle_sleep(unsigned long long nsecs);
+extern void os_idle_sleep(void);
 extern int os_timer_create(void);
 extern int os_timer_set_interval(unsigned long long nsecs);
 extern int os_timer_one_shot(unsigned long long nsecs);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 0fcdc374a9a1a2aee5d9049e8b93a1be3ccd3fad..a85c48ac2b273361a3d36e38b0595ed3d7b9d6d7 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -205,13 +205,10 @@ void initial_thread_cb(void (*proc)(void *), void *arg)
 
 static void um_idle_sleep(void)
 {
-	unsigned long long duration = UM_NSEC_PER_SEC;
-
-	if (time_travel_mode != TT_MODE_OFF) {
-		time_travel_sleep(duration);
-	} else {
-		os_idle_sleep(duration);
-	}
+	if (time_travel_mode != TT_MODE_OFF)
+		time_travel_sleep();
+	else
+		os_idle_sleep();
 }
 
 void arch_cpu_idle(void)
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 8dafc3f2add42004a41ca68341ed619268909255..8e8eb8ba04a49966b5f9dddfb978a61e20588a9e 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -46,6 +46,9 @@ static void time_travel_set_time(unsigned long long ns)
 	if (unlikely(ns < time_travel_time))
 		panic("time-travel: time goes backwards %lld -> %lld\n",
 		      time_travel_time, ns);
+	else if (unlikely(ns >= S64_MAX))
+		panic("The system was going to sleep forever, aborting");
+
 	time_travel_time = ns;
 }
 
@@ -399,9 +402,14 @@ static void time_travel_oneshot_timer(struct time_travel_event *e)
 	deliver_alarm();
 }
 
-void time_travel_sleep(unsigned long long duration)
+void time_travel_sleep(void)
 {
-	unsigned long long next = time_travel_time + duration;
+	/*
+	 * Wait "forever" (using S64_MAX because there are some potential
+	 * wrapping issues, especially with the current TT_MODE_EXTERNAL
+	 * controller application.
+	 */
+	unsigned long long next = S64_MAX;
 
 	if (time_travel_mode == TT_MODE_BASIC)
 		os_timer_disable();
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index 90f6de224c700d76402a36b598c199f08b217143..a61cbf73a179dec6a4bf55595c3d5906057c3c38 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -7,6 +7,7 @@
  */
 
 #include <stddef.h>
+#include <unistd.h>
 #include <errno.h>
 #include <signal.h>
 #include <time.h>
@@ -99,19 +100,9 @@ long long os_nsecs(void)
 }
 
 /**
- * os_idle_sleep() - sleep for a given time of nsecs
- * @nsecs: nanoseconds to sleep
+ * os_idle_sleep() - sleep until interrupted
  */
-void os_idle_sleep(unsigned long long nsecs)
+void os_idle_sleep(void)
 {
-	struct timespec ts = {
-		.tv_sec  = nsecs / UM_NSEC_PER_SEC,
-		.tv_nsec = nsecs % UM_NSEC_PER_SEC
-	};
-
-	/*
-	 * Relay the signal if clock_nanosleep is interrupted.
-	 */
-	if (clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL))
-		deliver_alarm();
+	pause();
 }