diff --git a/ROSBRIDGE_PROTOCOL.md b/ROSBRIDGE_PROTOCOL.md
index e58850d61..4a7e82468 100644
--- a/ROSBRIDGE_PROTOCOL.md
+++ b/ROSBRIDGE_PROTOCOL.md
@@ -93,12 +93,12 @@ ROS operations:
     * **call_service** - a service call
     * **service_response** - a service response
   * Actions:
-   * **advertise_action** - advertise an external action server
-   * **unadvertise_action** - unadvertise an external action server
-   * **send_action_goal** - a goal sent to an action server
-   * **cancel_action_goal** - cancel an in-progress action goal
-   * **action_feedback** - feedback messages from an action server
-   * **action_result** - an action result
+    * **advertise_action** - advertise an external action server
+    * **unadvertise_action** - unadvertise an external action server
+    * **send_action_goal** - a goal sent to an action server
+    * **cancel_action_goal** - cancel an in-progress action goal
+    * **action_feedback** - feedback messages from an action server
+    * **action_result** - an action result
 
 In general, actions or operations that the client takes (such as publishing and
 subscribing) have opcodes which are verbs (subscribe, call_service, unadvertise
diff --git a/rosbridge_library/src/rosbridge_library/internal/subscribers.py b/rosbridge_library/src/rosbridge_library/internal/subscribers.py
index 0bb94a809..a64c90b7f 100644
--- a/rosbridge_library/src/rosbridge_library/internal/subscribers.py
+++ b/rosbridge_library/src/rosbridge_library/internal/subscribers.py
@@ -176,6 +176,11 @@ def subscribe(self, client_id, callback):
             # In any case, the first message is handled using new_sub_callback,
             # which adds the new callback to the subscriptions dictionary.
             self.new_subscriptions.update({client_id: callback})
+            infos = self.node_handle.get_publishers_info_by_topic(self.topic)
+            if any(pub.qos_profile.durability == DurabilityPolicy.TRANSIENT_LOCAL for pub in infos):
+                self.qos.durability = DurabilityPolicy.TRANSIENT_LOCAL
+            if any(pub.qos_profile.reliability == ReliabilityPolicy.BEST_EFFORT for pub in infos):
+                self.qos.reliability = ReliabilityPolicy.BEST_EFFORT
             if self.new_subscriber is None:
                 self.new_subscriber = self.node_handle.create_subscription(
                     self.msg_class,
@@ -196,7 +201,7 @@ def unsubscribe(self, client_id):
         with self.rlock:
             if client_id in self.new_subscriptions:
                 del self.new_subscriptions[client_id]
-            else:
+            if client_id in self.subscriptions:
                 del self.subscriptions[client_id]
 
     def has_subscribers(self):