diff --git a/base-nova/src/base/pager/pager.cc b/base-nova/src/base/pager/pager.cc
index 59c486e52..2446789b4 100644
--- a/base-nova/src/base/pager/pager.cc
+++ b/base-nova/src/base/pager/pager.cc
@@ -275,6 +275,8 @@ Pager_object::Pager_object(unsigned long badge, unsigned affinity)
 	_state.singlestep    = false;
 	_state.sel_client_ec = Native_thread::INVALID_INDEX;
 
+	/* tell thread starting code on which CPU to let run the pager */
+	*reinterpret_cast<addr_t *>(stack_top()) = affinity;
 	/* creates local EC */
 	Thread_base::start();
 
diff --git a/base-nova/src/base/server/server.cc b/base-nova/src/base/server/server.cc
index a6d3c0b18..8662a2823 100644
--- a/base-nova/src/base/server/server.cc
+++ b/base-nova/src/base/server/server.cc
@@ -252,11 +252,16 @@ Rpc_entrypoint::Rpc_entrypoint(Cap_session *cap_session, size_t stack_size,
 			throw Cpu_session::Thread_creation_failed();
 		_tid.ec_sel = ec_cap.local_name();
 	}
-	else
+	else {
+		enum { CPU_NO = 0 }; //XXX find out the boot cpu
+		/* tell thread starting code on which CPU to let run the server thread */
+		*reinterpret_cast<addr_t *>(stack_top()) = CPU_NO;
+
 		/*
 		 * Required for core threads (creates local EC)
 		 */
 		Thread_base::start();
+	}
 
 	/* create cleanup portal */
 	_cap = _cap_session->alloc(Native_capability(_tid.ec_sel),
diff --git a/base-nova/src/base/thread/thread_nova.cc b/base-nova/src/base/thread/thread_nova.cc
index ae4ecb204..2a928c22e 100644
--- a/base-nova/src/base/thread/thread_nova.cc
+++ b/base-nova/src/base/thread/thread_nova.cc
@@ -121,6 +121,7 @@ void Thread_base::start()
 
 	/* create EC at core */
 	addr_t thread_sp = reinterpret_cast<addr_t>(&_context->stack[-4]);
+	thread_sp &= ~0xf; /* align initial stack to 16 byte boundary */
 
 	Thread_state state;
 	state.sel_exc_base = _tid.exc_pt_sel;
diff --git a/base-nova/src/core/thread_start.cc b/base-nova/src/core/thread_start.cc
index 68621a0df..ae49c18a4 100644
--- a/base-nova/src/core/thread_start.cc
+++ b/base-nova/src/core/thread_start.cc
@@ -77,15 +77,17 @@ void Thread_base::start()
 	 */
 	using namespace Nova;
 
-	addr_t sp = reinterpret_cast<addr_t>(&_context->stack[-4]);
-	addr_t utcb = reinterpret_cast<addr_t>(&_context->utcb);
+	addr_t sp       = reinterpret_cast<addr_t>(&_context->stack[-4]);
+	sp             &= ~0xf; /* align initial stack to 16 byte boundary */
+	addr_t utcb     = reinterpret_cast<addr_t>(&_context->utcb);
 	Utcb * utcb_obj = reinterpret_cast<Utcb *>(&_context->utcb);
-	addr_t pd_sel = Platform_pd::pd_core_sel();
+	addr_t pd_sel   = Platform_pd::pd_core_sel();
+	addr_t cpu_no   = *reinterpret_cast<addr_t *>(stack_top());
 
 	/* create local EC */
-	enum { CPU_NO = 0, GLOBAL = false };
-	uint8_t res = create_ec(_tid.ec_sel, pd_sel, CPU_NO,
-	                        utcb, sp, _tid.exc_pt_sel, GLOBAL);
+	enum { LOCAL_THREAD = false };
+	uint8_t res = create_ec(_tid.ec_sel, pd_sel, cpu_no,
+	                        utcb, sp, _tid.exc_pt_sel, LOCAL_THREAD);
 	if (res != NOVA_OK) {
 		PERR("create_ec returned %d", res);
 		throw Cpu_session::Thread_creation_failed();