diff --git a/CHANGELOG.md b/CHANGELOG.md
index ce177340..0a90627e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ Airbrake Ruby Changelog
   ([#146](https://github.com/airbrake/airbrake/pull/146))
 * **IMPORTANT:** added the promise API
   ([#143](https://github.com/airbrake/airbrake-ruby/pull/143))
+* **IMPORTANT:** deprecated the `component/action` API (when setting through
+  `params`) ([#151](https://github.com/airbrake/airbrake-ruby/pull/151))
 * Improved JRuby parsing of frames which include classloader
   ([#140](https://github.com/airbrake/airbrake-ruby/pull/140))
 * Fixed bug in the `host` option, when it is configured with a slug
diff --git a/lib/airbrake-ruby/notice.rb b/lib/airbrake-ruby/notice.rb
index 444c8f68..b8b3c9f0 100644
--- a/lib/airbrake-ruby/notice.rb
+++ b/lib/airbrake-ruby/notice.rb
@@ -140,6 +140,17 @@ def []=(key, value)
     private
 
     def context(params)
+      # DEPRECATION: remove the following code in the next MINOR release.
+      if params.key?(:component) || params.key?(:action)
+        @config.logger.warn(
+          "#{LOG_LABEL} passing component/action keys in the params hash is " \
+          "deprecated and will be removed soon. Please update your code to use " \
+          "`Airbrake.build_notice` and set these keys like this:\n" \
+          "  notice[:context][:component] = 'mycomponent'\n" \
+          "  notice[:context][:action] = 'myaction'"
+        )
+      end
+
       ctx = {
         version: @config.app_version,
         # We ensure that root_directory is always a String, so it can always be
@@ -148,6 +159,7 @@ def context(params)
         rootDirectory: @config.root_directory.to_s,
         environment: @config.environment,
 
+        # DEPRECATION: remove the following code in the next MINOR release.
         # Legacy Airbrake v4 behaviour.
         component: params.delete(:component),
         action: params.delete(:action),