diff --git a/repos/os/include/os/timed_semaphore.h b/repos/os/include/os/timed_semaphore.h
index ec9e7340e..bf42178f1 100644
--- a/repos/os/include/os/timed_semaphore.h
+++ b/repos/os/include/os/timed_semaphore.h
@@ -40,7 +40,7 @@ namespace Genode {
 /**
  * Alarm thread, which counts jiffies and triggers timeout events.
  */
-class Genode::Timeout_thread : public Thread_deprecated<4096>,
+class Genode::Timeout_thread : public Thread_deprecated<2048*sizeof(long)>,
                                public Alarm_scheduler
 {
 	private:
@@ -55,7 +55,7 @@ class Genode::Timeout_thread : public Thread_deprecated<4096>,
 
 	public:
 
-		Timeout_thread() : Thread_deprecated<4096>("alarm-timer")
+		Timeout_thread() : Thread_deprecated("alarm-timer")
 		{
 			_timer.sigh(_receiver.manage(&_context));
 			_timer.trigger_periodic(JIFFIES_STEP_MS*1000);
diff --git a/repos/ports/src/app/netperf/timer.cc b/repos/ports/src/app/netperf/timer.cc
index d2faae9bd..3603c9576 100644
--- a/repos/ports/src/app/netperf/timer.cc
+++ b/repos/ports/src/app/netperf/timer.cc
@@ -18,7 +18,7 @@
 
 using namespace Genode;
 
-class Alarm_thread : Thread_deprecated<4096>, public Alarm_scheduler
+class Alarm_thread : Thread_deprecated<2048*sizeof(long)>, public Alarm_scheduler
 {
 	private: