diff --git a/gmqtt/__init__.py b/gmqtt/__init__.py
index 93dc429..3679b0f 100644
--- a/gmqtt/__init__.py
+++ b/gmqtt/__init__.py
@@ -13,7 +13,7 @@
     "Mikhail Turchunovich",
     "Elena Nikolaichik"
 ]
-__version__ = "0.6.7"
+__version__ = "0.6.8"
 
 
 __all__ = [
diff --git a/gmqtt/client.py b/gmqtt/client.py
index afa35d5..860afc0 100644
--- a/gmqtt/client.py
+++ b/gmqtt/client.py
@@ -17,7 +17,7 @@
 
 class Message:
     def __init__(self, topic, payload, qos=0, retain=False, **kwargs):
-        self.topic = topic
+        self.topic = topic.encode('utf-8', errors='replace') if isinstance(topic, str) else str
         self.qos = qos
         self.retain = retain
         self.dup = False
diff --git a/gmqtt/mqtt/package.py b/gmqtt/mqtt/package.py
index 4f2c62a..5b87b8b 100644
--- a/gmqtt/mqtt/package.py
+++ b/gmqtt/mqtt/package.py
@@ -150,8 +150,12 @@ def build_package(cls, subscriptions, protocol, **kwargs) -> Tuple[int, bytes]:
         subscription_identifier = kwargs.get('subscription_identifier', cls.sentinel)
 
         for s in subscriptions:
-            remaining_length += 2 + len(s.topic) + 1
-            topics.append(s.topic)
+            topic = s.topic
+            if isinstance(topic, str):
+                topic = topic.encode()
+
+            remaining_length += 2 + len(topic) + 1
+            topics.append(topic)
 
             # if subscription_identifier hasn't been passed in kwargs,
             # we will use the first identifier for all subscriptions;