diff --git a/os/include/timer_session/timer_session.h b/os/include/timer_session/timer_session.h
index 026b445e3..4fa766ba4 100644
--- a/os/include/timer_session/timer_session.h
+++ b/os/include/timer_session/timer_session.h
@@ -36,6 +36,9 @@ namespace Timer {
 
 		/**
 		 * Program periodic timeout (in microseconds)
+		 *
+		 * The first period will be triggered after 'us' at the latest,
+		 * but it might be triggered earlier as well.
 		 */
 		virtual void trigger_periodic(unsigned us) = 0;
 
diff --git a/os/src/drivers/timer/include/timer_session_component.h b/os/src/drivers/timer/include/timer_session_component.h
index 549c0fdbd..130e9ff94 100644
--- a/os/src/drivers/timer/include/timer_session_component.h
+++ b/os/src/drivers/timer/include/timer_session_component.h
@@ -110,6 +110,7 @@ namespace Timer {
 
 			void sigh(Signal_context_capability sigh) { _sigh = sigh; }
 			void periodic(bool periodic) { _periodic = periodic; }
+			bool periodic() { return _periodic; }
 
 
 			/*********************
@@ -182,10 +183,13 @@ namespace Timer {
 			/**
 			 * Called from the '_trigger' function executed by the server activation
 			 */
-			void schedule_timeout(Genode::Alarm *alarm, Genode::Alarm::Time timeout)
+			void schedule_timeout(Wake_up_alarm *alarm, Genode::Alarm::Time timeout)
 			{
 				Alarm::Time now = _platform_timer->curr_time();
-				schedule_absolute(alarm, now + timeout);
+				if (alarm->periodic()) {
+					handle(now); /* update '_now' in 'Alarm_scheduler' */
+					schedule(alarm, timeout);
+				} else schedule_absolute(alarm, now + timeout);
 
 				/* interrupt current 'wait_for_timeout' */
 				_platform_timer->schedule_timeout(0);
@@ -258,7 +262,7 @@ namespace Timer {
 			unsigned long elapsed_ms() const
 			{
 				unsigned long const now = _timeout_scheduler.curr_time();
-				return now - _initial_time;
+				return (now - _initial_time) / 1000;
 			}
 
 			void msleep(unsigned) { /* never called at the server side */ }
diff --git a/os/src/test/timer/main.cc b/os/src/test/timer/main.cc
index ce4a5cbe4..128f5de63 100644
--- a/os/src/test/timer/main.cc
+++ b/os/src/test/timer/main.cc
@@ -91,6 +91,34 @@ int main(int argc, char **argv)
 	main_timer.msleep(2000);
 	printf("timeout fired\n");
 
+	/* check periodic timeouts */
+	Signal_receiver           sig_rcv;
+	Signal_context            sig_cxt;
+	Signal_context_capability sig = sig_rcv.manage(&sig_cxt);
+	main_timer.sigh(sig);
+	enum { PTEST_TIME_US = 2000000 };
+	unsigned period_us = 500000, periods = PTEST_TIME_US / period_us, i = 0;
+	printf("start periodic timeouts\n");
+	for (unsigned j = 0; j < 5; j++) {
+		unsigned elapsed_ms = main_timer.elapsed_ms();
+		main_timer.trigger_periodic(period_us);
+		while (i < periods) {
+			Signal s = sig_rcv.wait_for_signal();
+			i += s.num();
+		}
+		elapsed_ms = main_timer.elapsed_ms() - elapsed_ms;
+		unsigned const min_ms = ((i - 1) * period_us) / 1000;
+		unsigned const max_ms = (i * period_us) / 1000;
+		if (min_ms > elapsed_ms || max_ms < elapsed_ms) {
+			PERR("Timing %u ms period %u times failed: %u ms (min %u, max %u)",
+			     period_us / 1000, i, elapsed_ms, min_ms, max_ms);
+			return -1;
+		}
+		printf("Done %u ms period %u times: %u ms (min %u, max %u)\n",
+		       period_us / 1000, i, elapsed_ms, min_ms, max_ms);
+		i = 0, period_us /= 2, periods = PTEST_TIME_US / period_us;
+	}
+
 	/* create timer clients with different periods */
 	for (unsigned period_msec = 1; period_msec < 28; period_msec++) {
 		Timer_client *tc = new (env()->heap()) Timer_client(period_msec);