diff --git a/libweave/src/commands/cloud_command_proxy.h b/libweave/src/commands/cloud_command_proxy.h
index 5e3d42c..7998df6 100644
--- a/libweave/src/commands/cloud_command_proxy.h
+++ b/libweave/src/commands/cloud_command_proxy.h
@@ -25,7 +25,7 @@
 class CommandInstance;
 
 // Command proxy which publishes command updates to the cloud.
-class CloudCommandProxy final : public CommandProxyInterface {
+class CloudCommandProxy final : public CommandObserver {
  public:
   CloudCommandProxy(CommandInstance* command_instance,
                     CloudCommandUpdateInterface* cloud_command_updater,
diff --git a/libweave/src/commands/cloud_command_proxy_unittest.cc b/libweave/src/commands/cloud_command_proxy_unittest.cc
index 69e0b4b..06ff331 100644
--- a/libweave/src/commands/cloud_command_proxy_unittest.cc
+++ b/libweave/src/commands/cloud_command_proxy_unittest.cc
@@ -156,7 +156,7 @@
                               &state_change_queue_,
                               std::move(backoff),
                               task_runner_}};
-    command_instance_->AddProxy(proxy.release());
+    command_instance_->AddObserver(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 04401d1..2cfe3d5 100644
--- a/libweave/src/commands/command_instance.cc
+++ b/libweave/src/commands/command_instance.cc
@@ -39,9 +39,8 @@
 }
 
 CommandInstance::~CommandInstance() {
-  for (auto& proxy : proxies_) {
-    proxy->OnCommandDestroyed();
-  }
+  for (auto observer : observers_)
+    observer->OnCommandDestroyed();
 }
 
 const std::string& CommandInstance::GetCategory() const {
@@ -173,17 +172,16 @@
   return json;
 }
 
-void CommandInstance::AddProxy(CommandProxyInterface* proxy) {
-  proxies_.push_back(proxy);
+void CommandInstance::AddObserver(CommandObserver* observer) {
+  observers_.push_back(observer);
 }
 
 bool CommandInstance::SetResults(const native_types::Object& results) {
   // TODO(antonm): Add validation.
   if (results != results_) {
     results_ = results;
-    for (auto& proxy : proxies_) {
-      proxy->OnResultsChanged();
-    }
+    for (auto observer : observers_)
+      observer->OnResultsChanged();
   }
   return true;
 }
@@ -193,9 +191,8 @@
   SetStatus(kStatusInProgress);
   if (progress != progress_) {
     progress_ = progress;
-    for (auto& proxy : proxies_) {
-      proxy->OnProgressChanged();
-    }
+    for (auto observer : observers_)
+      observer->OnProgressChanged();
   }
   return true;
 }
@@ -221,9 +218,8 @@
 void CommandInstance::SetStatus(const std::string& status) {
   if (status != status_) {
     status_ = status;
-    for (auto& proxy : proxies_) {
-      proxy->OnStatusChanged();
-    }
+    for (auto observer : observers_)
+      observer->OnStatusChanged();
   }
 }
 
diff --git a/libweave/src/commands/command_instance.h b/libweave/src/commands/command_instance.h
index ba11985..d80e0b9 100644
--- a/libweave/src/commands/command_instance.h
+++ b/libweave/src/commands/command_instance.h
@@ -25,7 +25,7 @@
 
 class CommandDefinition;
 class CommandDictionary;
-class CommandProxyInterface;
+class CommandObserver;
 class CommandQueue;
 
 class CommandInstance final : public Command {
@@ -81,9 +81,9 @@
   // Sets the command ID (normally done by CommandQueue when the command
   // instance is added to it).
   void SetID(const std::string& id) { id_ = id; }
-  // Adds a proxy for this command.
-  // The proxy object is not owned by this class.
-  void AddProxy(CommandProxyInterface* proxy);
+  // Adds a observer for this command. The observer object is not owned by this
+  // class.
+  void AddObserver(CommandObserver* observer);
   // Sets the pointer to queue this command is part of.
   void SetCommandQueue(CommandQueue* queue) { queue_ = queue; }
 
@@ -141,8 +141,8 @@
   native_types::Object results_;
   // Current command status.
   std::string status_ = kStatusQueued;
-  // Command proxies for the command.
-  std::vector<CommandProxyInterface*> proxies_;
+  // Command observer for the command.
+  std::vector<CommandObserver*> 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/commands/command_proxy_interface.h b/libweave/src/commands/command_proxy_interface.h
index bf03f34..3aeb9bb 100644
--- a/libweave/src/commands/command_proxy_interface.h
+++ b/libweave/src/commands/command_proxy_interface.h
@@ -14,9 +14,9 @@
 // This interface lets the command instance to update its proxy of command
 // state changes, so that the proxy can then notify clients of the changes over
 // their supported protocol (e.g. D-Bus).
-class CommandProxyInterface {
+class CommandObserver {
  public:
-  virtual ~CommandProxyInterface() = default;
+  virtual ~CommandObserver() = default;
 
   virtual void OnResultsChanged() = 0;
   virtual void OnStatusChanged() = 0;
diff --git a/libweave/src/commands/dbus_command_dispatcher.cc b/libweave/src/commands/dbus_command_dispatcher.cc
index 6800660..7c7cfdc 100644
--- a/libweave/src/commands/dbus_command_dispatcher.cc
+++ b/libweave/src/commands/dbus_command_dispatcher.cc
@@ -27,7 +27,7 @@
       object_manager_.get(), object_manager_->GetBus(), command_instance,
       buffet::kCommandServicePathPrefix + std::to_string(++next_id_))};
   proxy->RegisterAsync(AsyncEventSequencer::GetDefaultCompletionAction());
-  command_instance->AddProxy(proxy.release());
+  command_instance->AddObserver(proxy.release());
 }
 
 }  // namespace weave
diff --git a/libweave/src/commands/dbus_command_dispatcher_unittest.cc b/libweave/src/commands/dbus_command_dispatcher_unittest.cc
index e97aa53..7f1ac9a 100644
--- a/libweave/src/commands/dbus_command_dispatcher_unittest.cc
+++ b/libweave/src/commands/dbus_command_dispatcher_unittest.cc
@@ -115,8 +115,8 @@
   }
 
   DBusCommandProxy* FindProxy(CommandInstance* command_instance) {
-    CHECK_EQ(command_instance->proxies_.size(), 1U);
-    return static_cast<DBusCommandProxy*>(command_instance->proxies_[0]);
+    CHECK_EQ(command_instance->observers_.size(), 1U);
+    return static_cast<DBusCommandProxy*>(command_instance->observers_[0]);
   }
 
   void FinishCommand(DBusCommandProxy* proxy) { proxy->Done(); }
diff --git a/libweave/src/commands/dbus_command_proxy.h b/libweave/src/commands/dbus_command_proxy.h
index 6780766..3f802ed 100644
--- a/libweave/src/commands/dbus_command_proxy.h
+++ b/libweave/src/commands/dbus_command_proxy.h
@@ -24,7 +24,7 @@
 
 class CommandInstance;
 
-class DBusCommandProxy : public CommandProxyInterface,
+class DBusCommandProxy : public CommandObserver,
                          public org::chromium::Buffet::CommandInterface {
  public:
   DBusCommandProxy(chromeos::dbus_utils::ExportedObjectManager* object_manager,
diff --git a/libweave/src/commands/dbus_command_proxy_unittest.cc b/libweave/src/commands/dbus_command_proxy_unittest.cc
index 7ae20ce..32a36b6 100644
--- a/libweave/src/commands/dbus_command_proxy_unittest.cc
+++ b/libweave/src/commands/dbus_command_proxy_unittest.cc
@@ -109,9 +109,9 @@
     EXPECT_CALL(*mock_exported_object_command_, ExportMethod(_, _, _, _))
         .Times(AnyNumber());
 
-    std::unique_ptr<CommandProxyInterface> command_proxy(
+    std::unique_ptr<CommandObserver> command_proxy(
         new DBusCommandProxy(nullptr, bus_, command_instance_.get(), cmd_path));
-    command_instance_->AddProxy(command_proxy.release());
+    command_instance_->AddObserver(command_proxy.release());
     GetCommandProxy()->RegisterAsync(
         AsyncEventSequencer::GetDefaultCompletionAction());
   }
@@ -124,8 +124,8 @@
   }
 
   DBusCommandProxy* GetCommandProxy() const {
-    CHECK_EQ(command_instance_->proxies_.size(), 1U);
-    return static_cast<DBusCommandProxy*>(command_instance_->proxies_[0]);
+    CHECK_EQ(command_instance_->observers_.size(), 1U);
+    return static_cast<DBusCommandProxy*>(command_instance_->observers_[0]);
   }
 
   org::chromium::Buffet::CommandAdaptor* GetCommandAdaptor() const {
diff --git a/libweave/src/device_registration_info.cc b/libweave/src/device_registration_info.cc
index 340fb40..fdc933c 100644
--- a/libweave/src/device_registration_info.cc
+++ b/libweave/src/device_registration_info.cc
@@ -938,13 +938,10 @@
               << "' arrived, ID: " << command_instance->GetID();
     std::unique_ptr<chromeos::BackoffEntry> backoff_entry{
         new chromeos::BackoffEntry{cloud_backoff_policy_.get()}};
-    std::unique_ptr<CommandProxyInterface> cloud_proxy{
-        new CloudCommandProxy{command_instance.get(),
-                              this,
-                              state_manager_->GetStateChangeQueue(),
-                              std::move(backoff_entry),
-                              task_runner_}};
-    command_instance->AddProxy(cloud_proxy.release());
+    std::unique_ptr<CommandObserver> cloud_proxy{new CloudCommandProxy{
+        command_instance.get(), this, state_manager_->GetStateChangeQueue(),
+        std::move(backoff_entry), task_runner_}};
+    command_instance->AddObserver(cloud_proxy.release());
     command_manager_->AddCommand(std::move(command_instance));
   }
 }