diff --git a/lib/annotate/annotate_models.rb b/lib/annotate/annotate_models.rb
index 266699c3b..2710cda24 100644
--- a/lib/annotate/annotate_models.rb
+++ b/lib/annotate/annotate_models.rb
@@ -171,7 +171,7 @@ def files_by_pattern(root_directory, pattern_type, options)
       when 'controller'
         [File.join(root_directory, CONTROLLER_DIR, "%PLURALIZED_MODEL_NAME%_controller.rb")]
       when 'admin'
-        [File.join(root_directory, ACTIVEADMIN_DIR, "%MODEL_NAME%.rb")]
+        [File.join(root_directory, ACTIVEADMIN_DIR, "%PLURALIZED_MODEL_NAME%.rb")]
       when 'helper'
         [File.join(root_directory, HELPER_DIR, "%PLURALIZED_MODEL_NAME%_helper.rb")]
       else