diff --git a/repos/base-hw/include/base/native_types.h b/repos/base-hw/include/base/native_types.h
index f271b55f52..4c1a2eb94d 100644
--- a/repos/base-hw/include/base/native_types.h
+++ b/repos/base-hw/include/base/native_types.h
@@ -27,7 +27,6 @@
 namespace Genode
 {
 	class Platform_thread;
-	class Tlb;
 
 	typedef unsigned Native_thread_id;
 
diff --git a/repos/base-hw/include/kernel/interface.h b/repos/base-hw/include/kernel/interface.h
index 660f15d499..be951cbcc7 100644
--- a/repos/base-hw/include/kernel/interface.h
+++ b/repos/base-hw/include/kernel/interface.h
@@ -21,12 +21,10 @@ namespace Genode
 {
 	class Native_utcb;
 	class Platform_pd;
-	class Tlb;
 }
 
 namespace Kernel
 {
-	typedef Genode::Tlb          Tlb;
 	typedef Genode::addr_t       addr_t;
 	typedef Genode::size_t       size_t;
 	typedef Genode::Platform_pd  Platform_pd;
diff --git a/repos/base-hw/src/core/include/kernel/core_interface.h b/repos/base-hw/src/core/include/kernel/core_interface.h
index 31f3377ed0..49260cec13 100644
--- a/repos/base-hw/src/core/include/kernel/core_interface.h
+++ b/repos/base-hw/src/core/include/kernel/core_interface.h
@@ -141,12 +141,15 @@ namespace Kernel
 	 * \param cpu_id     kernel name of the targeted CPU
 	 * \param pd_id      kernel name of the targeted domain
 	 * \param utcb       core local pointer to userland thread-context
+	 *
+	 * \retval   0  suceeded
+	 * \retval !=0  failed
 	 */
-	inline Tlb * start_thread(unsigned const thread_id, unsigned const cpu_id,
-	                          unsigned const pd_id, Native_utcb * const utcb)
+	inline int start_thread(unsigned const thread_id, unsigned const cpu_id,
+	                        unsigned const pd_id, Native_utcb * const utcb)
 	{
-		return (Tlb *)call(call_id_start_thread(), thread_id, cpu_id, pd_id,
-		                   (Call_arg)utcb);
+		return call(call_id_start_thread(), thread_id, cpu_id, pd_id,
+		            (Call_arg)utcb);
 	}
 
 
diff --git a/repos/base-hw/src/core/kernel/thread.cc b/repos/base-hw/src/core/kernel/thread.cc
index 3a38e339ef..6b7600078b 100644
--- a/repos/base-hw/src/core/kernel/thread.cc
+++ b/repos/base-hw/src/core/kernel/thread.cc
@@ -295,26 +295,26 @@ void Thread::_call_start_thread()
 	Thread * const thread = Thread::pool()->object(user_arg_1());
 	if (!thread) {
 		PWRN("failed to lookup  thread");
-		user_arg_0(0);
+		user_arg_0(-1);
 		return;
 	}
 	/* lookup CPU */
 	Cpu * const cpu = cpu_pool()->cpu(user_arg_2());
 	if (!cpu) {
 		PWRN("failed to lookup CPU");
-		user_arg_0(0);
+		user_arg_0(-2);
 		return;
 	}
 	/* lookup domain */
 	Pd * const pd = Pd::pool()->object(user_arg_3());
 	if (!pd) {
 		PWRN("failed to lookup domain");
-		user_arg_0(0);
+		user_arg_0(-3);
 		return;
 	}
 	/* start thread */
 	thread->init(cpu, pd, (Native_utcb *)user_arg_4(), 1);
-	user_arg_0((Call_ret)thread->_pd->translation_table());
+	user_arg_0(0);
 }
 
 
diff --git a/repos/base-hw/src/core/platform_thread.cc b/repos/base-hw/src/core/platform_thread.cc
index b6511c2079..2686b722ed 100644
--- a/repos/base-hw/src/core/platform_thread.cc
+++ b/repos/base-hw/src/core/platform_thread.cc
@@ -206,7 +206,7 @@ int Platform_thread::start(void * const ip, void * const sp)
 	unsigned const cpu =
 		_location.valid() ? _location.xpos() : Cpu::primary_id();
 	_utcb_core_addr->start_info()->init(_id, _utcb);
-	if (!Kernel::start_thread(_id, cpu, _pd->id(), _utcb_core_addr)) {
+	if (Kernel::start_thread(_id, cpu, _pd->id(), _utcb_core_addr)) {
 		PERR("failed to start thread");
 		return -1;
 	}