diff --git a/espeakup.c b/espeakup.c
index d7f49f8..0cf3d0b 100644
--- a/espeakup.c
+++ b/espeakup.c
@@ -42,7 +42,7 @@ espeak_AUDIO_OUTPUT audio_mode;
 pthread_cond_t runner_awake = PTHREAD_COND_INITIALIZER;
 pthread_cond_t stop_acknowledged = PTHREAD_COND_INITIALIZER;
 pthread_mutex_t queue_guard = PTHREAD_MUTEX_INITIALIZER;
-pthread_mutex_t stop_guard = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t acknowledge_guard = PTHREAD_MUTEX_INITIALIZER;
 
 int espeakup_is_running(void)
 {
diff --git a/espeakup.h b/espeakup.h
index c529ad4..d5d3f18 100644
--- a/espeakup.h
+++ b/espeakup.h
@@ -88,6 +88,6 @@ extern espeak_AUDIO_OUTPUT audio_mode;
 extern pthread_cond_t runner_awake;
 extern pthread_cond_t stop_acknowledged;
 extern pthread_mutex_t queue_guard;
-extern pthread_mutex_t stop_guard;
+extern pthread_mutex_t acknowledge_guard;
 
 #endif
diff --git a/softsynth.c b/softsynth.c
index a78cc23..37e70b3 100644
--- a/softsynth.c
+++ b/softsynth.c
@@ -167,11 +167,20 @@ static void process_buffer(struct synth_t *s, char *buf, ssize_t length)
 
 static void request_espeak_stop(void)
 {
-	pthread_mutex_lock(&stop_guard);
+	pthread_mutex_lock(&acknowledge_guard);
+	pthread_mutex_lock(&queue_guard);
 	runner_must_stop = 1;
+	pthread_mutex_unlock(&queue_guard);
 	pthread_cond_signal(&runner_awake);	/* Wake runner, if necessary. */
-	pthread_cond_wait(&stop_acknowledged, &stop_guard);
-	pthread_mutex_unlock(&stop_guard);
+
+	/*
+	 * Runner will see runner_must_stop == 1 next time it locks 
+	 * queue_guard, or when it awakens.
+	 * It will lock acknowledge_guard, acknowledge the stop, and signal
+	 * the reader, which will awaken.
+	 */
+	pthread_cond_wait(&stop_acknowledged, &acknowledge_guard);
+	pthread_mutex_unlock(&acknowledge_guard);
 }
 
 void *softsynth_thread(void *arg)
diff --git a/synth.c b/synth.c
index 39d95ea..1bfb0ce 100644
--- a/synth.c
+++ b/synth.c
@@ -148,7 +148,6 @@ static void queue_process_entry(struct synth_t *s)
 	espeak_ERROR error;
 	struct espeak_entry_t *current;
 
-	pthread_mutex_lock(&queue_guard);
 	current = (struct espeak_entry_t *) queue_peek();
 	pthread_mutex_unlock(&queue_guard);
 	if (current) {
@@ -198,14 +197,12 @@ static void queue_clear()
 {
 	struct espeak_entry_t *current;
 
-	pthread_mutex_lock(&queue_guard);
 	current = (struct espeak_entry_t *) queue_peek();
 	while (current) {
 		free_entry(current);
 		queue_remove();
 		current = (struct espeak_entry_t *) queue_peek();
 	}
-	pthread_mutex_unlock(&queue_guard);
 }
 
 /* espeak_thread is the "main" function of our secondary (queue-processing)
@@ -267,11 +264,11 @@ void *espeak_thread(void *arg)
 		}
 
 		if (runner_must_stop) {
-			pthread_mutex_lock(&stop_guard);
+			pthread_mutex_lock(&acknowledge_guard);
 			queue_clear();
 			stop_speech();
 			runner_must_stop = 0;
-			pthread_mutex_unlock(&stop_guard);
+			pthread_mutex_unlock(&acknowledge_guard);
 			pthread_cond_signal(&stop_acknowledged);
 		}
 	}