diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index c52ee650247..c857838c22e 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -2014,6 +2014,7 @@ class UsersController < ApplicationController
       result.merge!(params.permit(:active, :staged, :approved))
     end
 
+    deprecate_modify_user_params_method
     modify_user_params(result)
   end
 
@@ -2022,6 +2023,18 @@ class UsersController < ApplicationController
     attrs
   end
 
+  def deprecate_modify_user_params_method
+    # only issue a deprecation warning if the method is overriden somewhere
+    if method(:modify_user_params).source_location[0] !=
+         "#{Rails.root}/app/controllers/users_controller.rb"
+      Discourse.deprecate(
+        "`UsersController#modify_user_params` method is deprecated. Please use the `users_controller_update_user_params` modifier instead.",
+        since: "3.1.0.beta4",
+        drop_from: "3.2.0",
+      )
+    end
+  end
+
   def fail_with(key)
     render json: { success: false, message: I18n.t(key) }
   end