diff --git a/src/c/threads/mutex.d b/src/c/threads/mutex.d
index 3452bc894..cdd91a148 100755
--- a/src/c/threads/mutex.d
+++ b/src/c/threads/mutex.d
@@ -113,12 +113,15 @@ mp_giveup_lock(cl_object lock)
                 FEerror_not_owned(lock);
 	}
 	if (--lock->lock.counter == 0) {
-		lock->lock.owner = ECL_NIL;
-		print_lock("releasing %p\t", lock, lock);
-		ecl_wakeup_waiters(env, lock, ECL_WAKEUP_ONE);
-	} else {
-		print_lock("released %p\t", lock, lock);
-	}
+		cl_object first = ecl_waiter_pop(env, lock);;
+		if (first == ECL_NIL) {
+			lock->lock.owner = ECL_NIL;
+		} else {
+			lock->lock.counter = 1;
+			lock->lock.owner = first;
+			ecl_wakeup_process(first);
+		}
+	} 
         ecl_return1(env, ECL_T);
 }
 
@@ -158,6 +161,26 @@ mp_get_lock_nowait(cl_object lock)
 	ecl_return1(env, get_lock_inner(env, lock));
 }
 
+static cl_object
+own_or_get_lock(cl_env_ptr env, cl_object lock)
+{
+	cl_object output;
+	cl_object own_process = env->own_process;
+	ecl_disable_interrupts_env(env);
+        if (AO_compare_and_swap_full((AO_t*)&(lock->lock.owner),
+				     (AO_t)ECL_NIL, (AO_t)own_process)) {
+		lock->lock.counter = 1;
+		output = ECL_T;
+		print_lock("acquired %p\t", lock, lock);
+	} else if (lock->lock.owner == own_process) {
+		output = ECL_T;
+        } else {
+		output = ECL_NIL;
+	}
+	ecl_enable_interrupts_env(env);
+	return output;
+}
+
 cl_object
 mp_get_lock_wait(cl_object lock)
 {
@@ -166,7 +189,7 @@ mp_get_lock_wait(cl_object lock)
 		FEerror_not_a_lock(lock);
 	}
 	if (get_lock_inner(env, lock) == ECL_NIL) {
-		ecl_wait_on(env, get_lock_inner, lock);
+		ecl_wait_on(env, own_or_get_lock, lock);
 	}
 	@(return ECL_T)
 }
diff --git a/src/c/threads/queue.d b/src/c/threads/queue.d
index bb282f539..7aad83b00 100755
--- a/src/c/threads/queue.d
+++ b/src/c/threads/queue.d
@@ -302,6 +302,29 @@ ecl_wait_on(cl_env_ptr env, cl_object (*condition)(cl_env_ptr, cl_object), cl_ob
 #endif
 }
 
+cl_object
+ecl_waiter_pop(cl_env_ptr the_env, cl_object q)
+{
+	cl_object output;
+	ecl_disable_interrupts_env(the_env);
+	ecl_get_spinlock(the_env, &q->queue.spinlock);
+	{
+		cl_object l;
+		output = ECL_NIL;
+		for (l = q->queue.list; l != ECL_NIL; l = ECL_CONS_CDR(l)) {
+			cl_object p = ECL_CONS_CAR(l);
+			if (p->process.phase != ECL_PROCESS_INACTIVE &&
+			    p->process.phase != ECL_PROCESS_EXITING) {
+				output = p;
+				break;
+			}
+		}
+	}
+	ecl_giveup_spinlock(&q->queue.spinlock);
+	ecl_enable_interrupts_env(the_env);
+	return output;
+}
+
 void
 ecl_wakeup_waiters(cl_env_ptr the_env, cl_object q, int flags)
 {
diff --git a/src/h/internal.h b/src/h/internal.h
index e5ecdcdb6..191becde5 100755
--- a/src/h/internal.h
+++ b/src/h/internal.h
@@ -497,6 +497,7 @@ extern void ecl_giveup_spinlock(cl_object *lock);
 extern cl_object ecl_wait_on(cl_env_ptr env, cl_object (*condition)(cl_env_ptr, cl_object), cl_object o);
 extern void ecl_wakeup_waiters(cl_env_ptr the_env, cl_object o, int flags);
 extern void ecl_wakeup_process(cl_object process);
+extern cl_object ecl_waiter_pop(cl_env_ptr the_env, cl_object q);
 #endif
 
 /* threads/rwlock.d */