diff --git a/bin/tests/task_test.c b/bin/tests/task_test.c
index 866767159e..f48bd97b9a 100644
--- a/bin/tests/task_test.c
+++ b/bin/tests/task_test.c
@@ -42,6 +42,7 @@ main(int argc, char *argv[]) {
 	mem_context_t mctx = NULL;
 	task_manager_t manager = NULL;
 	task_t t1 = NULL, t2 = NULL;
+	task_t t3 = NULL, t4 = NULL;
 	generic_event_t event;
 	unsigned int workers;
 
@@ -57,27 +58,45 @@ main(int argc, char *argv[]) {
 
 	INSIST(task_create(manager, "1", my_shutdown, 0, &t1));
 	INSIST(task_create(manager, "2", my_shutdown, 0, &t2));
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t1, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t2, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t1, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t2, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t1, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t2, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t1, event);
-	event = event_get(mctx, 1, my_callback, sizeof *event);
-	task_send_event(t2, event);
+	INSIST(task_create(manager, "3", my_shutdown, 0, &t3));
+	INSIST(task_create(manager, "4", my_shutdown, 0, &t4));
+
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t1, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t2, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t3, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t4, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t2, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t3, event);
+	event = event_get(mctx, 1, my_callback, sizeof *event);
+	task_send_event(t4, event);
 
-	task_shutdown(t1);
-	task_shutdown(t2);
 	task_detach(&t1);
 	task_detach(&t2);
+	task_detach(&t3);
+	task_detach(&t4);
+
 	printf("destroy\n");
 	task_manager_destroy(&manager);
 	printf("destroyed\n");
diff --git a/lib/isc/include/isc/task.h b/lib/isc/include/isc/task.h
index c787ec299e..c3feb549e1 100644
--- a/lib/isc/include/isc/task.h
+++ b/lib/isc/include/isc/task.h
@@ -57,6 +57,7 @@ void *					event_get(mem_context_t,
 						  size_t);
 void					event_put(void *);
 
+
 /***
  *** Tasks.
  ***/
diff --git a/lib/isc/pthreads/include/isc/condition.h b/lib/isc/pthreads/include/isc/condition.h
index e0b1560506..1d8832d10c 100644
--- a/lib/isc/pthreads/include/isc/condition.h
+++ b/lib/isc/pthreads/include/isc/condition.h
@@ -22,7 +22,7 @@ typedef pthread_cond_t			os_condition_t;
 
 #else
 
-Error!  Condition variables are not meaningful for a non-threaded program.
+#error Condition variables are not meaningful for a non-threaded program.
 
 #endif
 
diff --git a/lib/isc/pthreads/include/isc/thread.h b/lib/isc/pthreads/include/isc/thread.h
index 97ee37d9c0..3afca332f3 100644
--- a/lib/isc/pthreads/include/isc/thread.h
+++ b/lib/isc/pthreads/include/isc/thread.h
@@ -14,6 +14,10 @@ typedef pthread_t			os_thread_t;
 					 == 0)
 #define os_thread_detach(t)		INSIST(pthread_detach((t)) == 0)
 
+#else
+
+#error Threads are not meaningful for a non-threaded program.
+
 #endif
 
 #endif /* THREAD_H */
diff --git a/lib/isc/task.c b/lib/isc/task.c
index 8bf849c430..cc3fec0105 100644
--- a/lib/isc/task.c
+++ b/lib/isc/task.c
@@ -11,6 +11,11 @@
 #define VALID_TASK(t)		((t) != NULL && \
 				 (t)->magic == TASK_MAGIC)
 
+/*
+ * We use macros instead of calling the os_ routines
+ * directly because the capital letters make the
+ * locking stand out.
+ */
 #define LOCK(lp)		os_mutex_lock((lp))
 #define UNLOCK(lp)		os_mutex_unlock((lp))
 #define WAIT(cvp, lp)		os_condition_wait((cvp), (lp))