diff --git a/lib/appsignal/sourcemap/hook.rb b/lib/appsignal/sourcemap/hook.rb
index c97aa4e..a0dcb02 100644
--- a/lib/appsignal/sourcemap/hook.rb
+++ b/lib/appsignal/sourcemap/hook.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'appsignal/hooks'
+
 module Appsignal
   module Sourcemap
     class SourcemapHook < Appsignal::Hooks::Hook