diff --git a/pubsub.go b/pubsub.go
index 2bd156db..b64c8a4f 100644
--- a/pubsub.go
+++ b/pubsub.go
@@ -238,9 +238,17 @@ func (c *PubSub) Unsubscribe(ctx context.Context, channels ...string) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	for _, channel := range channels {
-		delete(c.channels, channel)
+	if len(channels) > 0 {
+		for _, channel := range channels {
+			delete(c.channels, channel)
+		}
+	} else {
+		// Unsubscribe from all channels.
+		for channel := range c.channels {
+			delete(c.channels, channel)
+		}
 	}
+
 	err := c.subscribe(ctx, "unsubscribe", channels...)
 	return err
 }
@@ -251,9 +259,17 @@ func (c *PubSub) PUnsubscribe(ctx context.Context, patterns ...string) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	for _, pattern := range patterns {
-		delete(c.patterns, pattern)
+	if len(patterns) > 0 {
+		for _, pattern := range patterns {
+			delete(c.patterns, pattern)
+		}
+	} else {
+		// Unsubscribe from all patterns.
+		for pattern := range c.patterns {
+			delete(c.patterns, pattern)
+		}
 	}
+
 	err := c.subscribe(ctx, "punsubscribe", patterns...)
 	return err
 }
@@ -264,9 +280,17 @@ func (c *PubSub) SUnsubscribe(ctx context.Context, channels ...string) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	for _, channel := range channels {
-		delete(c.schannels, channel)
+	if len(channels) > 0 {
+		for _, channel := range channels {
+			delete(c.schannels, channel)
+		}
+	} else {
+		// Unsubscribe from all channels.
+		for channel := range c.schannels {
+			delete(c.schannels, channel)
+		}
 	}
+
 	err := c.subscribe(ctx, "sunsubscribe", channels...)
 	return err
 }