diff --git a/buffet/dbus_command_dispatcher.cc b/buffet/dbus_command_dispatcher.cc
index 39e106b..9bbb55e 100644
--- a/buffet/dbus_command_dispatcher.cc
+++ b/buffet/dbus_command_dispatcher.cc
@@ -30,7 +30,10 @@
       object_manager_.get(), object_manager_->GetBus(), command,
       buffet::kCommandServicePathPrefix + std::to_string(++next_id_))};
   proxy->RegisterAsync(AsyncEventSequencer::GetDefaultCompletionAction());
-  command->AddObserver(proxy.release());
+  // DBusCommandProxy::DBusCommandProxy() subscribe itself to weave::Command
+  // notifications. When weave::Command is being destroyed it sends
+  // ::OnCommandDestroyed() and DBusCommandProxy deletes itself.
+  proxy.release();
 }
 
 }  // namespace buffet
diff --git a/buffet/dbus_command_proxy.cc b/buffet/dbus_command_proxy.cc
index d53355a..f89ec52 100644
--- a/buffet/dbus_command_proxy.cc
+++ b/buffet/dbus_command_proxy.cc
@@ -20,7 +20,9 @@
                                    weave::Command* command,
                                    std::string object_path)
     : command_{command},
-      dbus_object_{object_manager, bus, dbus::ObjectPath{object_path}} {}
+      dbus_object_{object_manager, bus, dbus::ObjectPath{object_path}} {
+  observer_.Add(command);
+}
 
 void DBusCommandProxy::RegisterAsync(
     const AsyncEventSequencer::CompletionAction& completion_callback) {
diff --git a/buffet/dbus_command_proxy.h b/buffet/dbus_command_proxy.h
index 86d9c6e..7be3938 100644
--- a/buffet/dbus_command_proxy.h
+++ b/buffet/dbus_command_proxy.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include <base/macros.h>
+#include <base/scoped_observer.h>
 #include <chromeos/dbus/data_serialization.h>
 #include <chromeos/dbus/dbus_object.h>
 
@@ -59,6 +60,8 @@
   org::chromium::Buffet::CommandAdaptor dbus_adaptor_{this};
   chromeos::dbus_utils::DBusObject dbus_object_;
 
+  ScopedObserver<weave::Command, weave::Command::Observer> observer_{this};
+
   friend class DBusCommandProxyTest;
   friend class DBusCommandDispacherTest;
   DISALLOW_COPY_AND_ASSIGN(DBusCommandProxy);
diff --git a/libweave/include/weave/command.h b/libweave/include/weave/command.h
index 58a63fe..0533afa 100644
--- a/libweave/include/weave/command.h
+++ b/libweave/include/weave/command.h
@@ -30,18 +30,22 @@
   // This interface lets the command to notify clients about changes.
   class Observer {
    public:
-    virtual ~Observer() = default;
-
     virtual void OnResultsChanged() = 0;
     virtual void OnStatusChanged() = 0;
     virtual void OnProgressChanged() = 0;
     virtual void OnCommandDestroyed() = 0;
+
+   protected:
+    virtual ~Observer() = default;
   };
 
   // Adds an observer for this command. The observer object is not owned by this
   // class.
   virtual void AddObserver(Observer* observer) = 0;
 
+  // Removes an observer for this command.
+  virtual void RemoveObserver(Observer* observer) = 0;
+
   // Returns the full command ID.
   virtual const std::string& GetID() const = 0;
 
diff --git a/libweave/include/weave/mock_command.h b/libweave/include/weave/mock_command.h
index def903d..8addfea 100644
--- a/libweave/include/weave/mock_command.h
+++ b/libweave/include/weave/mock_command.h
@@ -22,6 +22,7 @@
   ~MockCommand() override = default;
 
   MOCK_METHOD1(AddObserver, void(Observer*));
+  MOCK_METHOD1(RemoveObserver, void(Observer*));
   MOCK_CONST_METHOD0(GetID, const std::string&());
   MOCK_CONST_METHOD0(GetName, const std::string&());
   MOCK_CONST_METHOD0(GetCategory, const std::string&());
diff --git a/libweave/src/commands/cloud_command_proxy.cc b/libweave/src/commands/cloud_command_proxy.cc
index a6685fc..b277802 100644
--- a/libweave/src/commands/cloud_command_proxy.cc
+++ b/libweave/src/commands/cloud_command_proxy.cc
@@ -28,6 +28,7 @@
   callback_token_ = state_change_queue_->AddOnStateUpdatedCallback(
       base::Bind(&CloudCommandProxy::OnDeviceStateUpdated,
                  weak_ptr_factory_.GetWeakPtr()));
+  observer_.Add(command_instance);
 }
 
 void CloudCommandProxy::OnResultsChanged() {
diff --git a/libweave/src/commands/cloud_command_proxy.h b/libweave/src/commands/cloud_command_proxy.h
index db03885..5f7d21c 100644
--- a/libweave/src/commands/cloud_command_proxy.h
+++ b/libweave/src/commands/cloud_command_proxy.h
@@ -13,6 +13,7 @@
 #include <base/macros.h>
 #include <base/memory/ref_counted.h>
 #include <base/memory/weak_ptr.h>
+#include <base/scoped_observer.h>
 #include <base/task_runner.h>
 #include <chromeos/backoff_entry.h>
 
@@ -90,6 +91,8 @@
   // successfully.
   UpdateID last_state_update_id_{0};
 
+  ScopedObserver<Command, Command::Observer> observer_{this};
+
   base::WeakPtrFactory<CloudCommandProxy> backoff_weak_ptr_factory_{this};
   base::WeakPtrFactory<CloudCommandProxy> weak_ptr_factory_{this};
   DISALLOW_COPY_AND_ASSIGN(CloudCommandProxy);
diff --git a/libweave/src/commands/cloud_command_proxy_unittest.cc b/libweave/src/commands/cloud_command_proxy_unittest.cc
index 7cc054e..f3e9b60 100644
--- a/libweave/src/commands/cloud_command_proxy_unittest.cc
+++ b/libweave/src/commands/cloud_command_proxy_unittest.cc
@@ -157,7 +157,10 @@
                               &state_change_queue_,
                               std::move(backoff),
                               task_runner_}};
-    command_instance_->AddObserver(proxy.release());
+    // CloudCommandProxy::CloudCommandProxy() subscribe itself to weave::Command
+    // notifications. When weave::Command is being destroyed it sends
+    // ::OnCommandDestroyed() and CloudCommandProxy deletes itself.
+    proxy.release();
   }
 
   StateChangeQueueInterface::UpdateID current_state_update_id_{0};
diff --git a/libweave/src/commands/command_instance.cc b/libweave/src/commands/command_instance.cc
index 8c4b89a..4e89dca 100644
--- a/libweave/src/commands/command_instance.cc
+++ b/libweave/src/commands/command_instance.cc
@@ -58,8 +58,7 @@
 }
 
 CommandInstance::~CommandInstance() {
-  for (auto observer : observers_)
-    observer->OnCommandDestroyed();
+  FOR_EACH_OBSERVER(Observer, observers_, OnCommandDestroyed());
 }
 
 const std::string& CommandInstance::GetID() const {
@@ -107,8 +106,7 @@
   SetStatus(CommandStatus::kInProgress);
   if (obj != progress_) {
     progress_ = obj;
-    for (auto observer : observers_)
-      observer->OnProgressChanged();
+    FOR_EACH_OBSERVER(Observer, observers_, OnProgressChanged());
   }
   return true;
 }
@@ -124,8 +122,7 @@
 
   if (obj != results_) {
     results_ = obj;
-    for (auto observer : observers_)
-      observer->OnResultsChanged();
+    FOR_EACH_OBSERVER(Observer, observers_, OnResultsChanged());
   }
   return true;
 }
@@ -251,7 +248,11 @@
 }
 
 void CommandInstance::AddObserver(Observer* observer) {
-  observers_.push_back(observer);
+  observers_.AddObserver(observer);
+}
+
+void CommandInstance::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
 }
 
 void CommandInstance::Abort() {
@@ -275,8 +276,7 @@
 void CommandInstance::SetStatus(CommandStatus status) {
   if (status != status_) {
     status_ = status;
-    for (auto observer : observers_)
-      observer->OnStatusChanged();
+    FOR_EACH_OBSERVER(Observer, observers_, OnStatusChanged());
   }
 }
 
diff --git a/libweave/src/commands/command_instance.h b/libweave/src/commands/command_instance.h
index 1b30d53..d709e2f 100644
--- a/libweave/src/commands/command_instance.h
+++ b/libweave/src/commands/command_instance.h
@@ -11,6 +11,7 @@
 #include <vector>
 
 #include <base/macros.h>
+#include <base/observer_list.h>
 #include <chromeos/errors/error.h>
 
 #include "libweave/src/commands/prop_values.h"
@@ -42,6 +43,7 @@
   // Command overrides.
   std::unique_ptr<base::DictionaryValue> ToJson() const override;
   void AddObserver(Observer* observer) override;
+  void RemoveObserver(Observer* observer) override;
   const std::string& GetID() const override;
   const std::string& GetName() const override;
   const std::string& GetCategory() const override;
@@ -109,8 +111,8 @@
   ValueMap results_;
   // Current command status.
   CommandStatus status_ = CommandStatus::kQueued;
-  // Command observer for the command.
-  std::vector<Observer*> observers_;
+  // Command observers.
+  base::ObserverList<Observer> observers_;
   // Pointer to the command queue this command instance is added to.
   // The queue owns the command instance, so it outlives this object.
   CommandQueue* queue_ = nullptr;
diff --git a/libweave/src/device_registration_info.cc b/libweave/src/device_registration_info.cc
index 1eddc21..ff35f5c 100644
--- a/libweave/src/device_registration_info.cc
+++ b/libweave/src/device_registration_info.cc
@@ -1012,10 +1012,13 @@
               << "' arrived, ID: " << command_instance->GetID();
     std::unique_ptr<chromeos::BackoffEntry> backoff_entry{
         new chromeos::BackoffEntry{cloud_backoff_policy_.get()}};
-    std::unique_ptr<Command::Observer> cloud_proxy{new CloudCommandProxy{
+    std::unique_ptr<CloudCommandProxy> cloud_proxy{new CloudCommandProxy{
         command_instance.get(), this, state_manager_->GetStateChangeQueue(),
         std::move(backoff_entry), task_runner_}};
-    command_instance->AddObserver(cloud_proxy.release());
+    // CloudCommandProxy::CloudCommandProxy() subscribe itself to weave::Command
+    // notifications. When weave::Command is being destroyed it sends
+    // ::OnCommandDestroyed() and CloudCommandProxy deletes itself.
+    cloud_proxy.release();
     command_manager_->AddCommand(std::move(command_instance));
   }
 }