diff --git a/app/services/foreman/renderer/scope/macros/loaders.rb b/app/services/foreman/renderer/scope/macros/loaders.rb
index ba930efb3a2..0fd15a72cd4 100644
--- a/app/services/foreman/renderer/scope/macros/loaders.rb
+++ b/app/services/foreman/renderer/scope/macros/loaders.rb
@@ -66,7 +66,7 @@ module Loaders
 <% end %>", desc: "Prints users in Europe, their login, when a user was logged on for the last time and the authentication source"
             end
             define_method name do |search: '', includes: nil, preload: nil, joins: nil, select: nil, batch: 1_000, limit: nil|
-              load_resource(klass: model, search: search, permission: permission, includes: includes, preload: preload, joins: joins, select: select, batch: batch, limit: limit)
+              load_resource(klass: model, search: search, permission: permission, includes: includes, preload: preload, joins: joins, select: select, batch: batch, limit: limit, defined_as: name)
             end
           end
 
@@ -76,9 +76,12 @@ module Loaders
           #   .each { |batch| batch.each { |record| record.name }}
           # or
           #   .each_record { |record| record.name }
-          def load_resource(klass:, search:, permission:, batch: 1_000, includes: nil, limit: nil, select: nil, joins: nil, where: nil, preload: nil)
+          def load_resource(klass:, search:, permission:, batch: 1_000, includes: nil, limit: nil, select: nil, joins: nil, where: nil, preload: nil, defined_as: __method__)
             limit ||= 10 if preview?
 
+            type_check!(defined_as, 'select', select, [Symbol, [Array, Symbol]])
+            type_check!(defined_as, 'joins', joins, [Symbol, Hash, [Array, Symbol]])
+
             base = klass
             base = base.search_for(search)
             base = base.preload(preload) unless preload.nil?
@@ -90,6 +93,18 @@ def load_resource(klass:, search:, permission:, batch: 1_000, includes: nil, lim
             base = base.select(select) unless select.nil?
             base.in_batches(of: batch)
           end
+
+          private
+
+          def type_check!(method, label, what, spec)
+            return if what.nil?
+            return if spec.any? { |type, subtype| what.is_a?(type) && (subtype.nil? || what.all? { |value| value.is_a?(subtype) }) }
+
+            options = spec.map { |type, subtype| subtype.nil? ? type : "#{type} of #{subtype.to_s.pluralize}" }
+            last = options.pop
+            options = options.join(', ') + " or #{last}"
+            raise ArgumentError, "Value of '#{label}' passed to #{method} must be #{options}"
+          end
         end
       end
     end
diff --git a/test/unit/foreman/renderer/scope/macros/loader_macros_test.rb b/test/unit/foreman/renderer/scope/macros/loader_macros_test.rb
new file mode 100644
index 00000000000..a8395bcf7af
--- /dev/null
+++ b/test/unit/foreman/renderer/scope/macros/loader_macros_test.rb
@@ -0,0 +1,49 @@
+require 'test_helper'
+
+class LoaderMacrosTest < ActiveSupport::TestCase
+  setup do
+    host = FactoryBot.build_stubbed(:host)
+    template = OpenStruct.new(
+      name: 'Test',
+      template: 'Test'
+    )
+    source = Foreman::Renderer::Source::Database.new(
+      template
+    )
+    @scope = Class.new(Foreman::Renderer::Scope::Base) do
+      include Foreman::Renderer::Scope::Macros::Base
+    end.send(:new, source: source)
+  end
+
+  describe '#load_resources' do
+    it 'should accept custom selects' do
+      @scope.load_hosts(select: :id)
+      @scope.load_hosts(select: [:id, :name])
+    end
+
+    it 'should reject unacceptable selects' do
+      assert_raises(ArgumentError) { @scope.load_hosts(select: 'a string value') }
+      assert_raises(ArgumentError) { @scope.load_hosts(select: {:key => :value}) }
+      assert_raises(ArgumentError) { @scope.load_hosts(select: [:mixed, 'array']) }
+      error = assert_raises(ArgumentError) { @scope.load_hosts(select: 7) }
+      assert_match /Value of 'select'/, error.message
+      assert_match /load_hosts/, error.message
+      assert_match /Symbol or Array of Symbols/, error.message
+    end
+
+    it 'should accept custom joins' do
+      @scope.load_hosts(joins: :interfaces)
+      @scope.load_hosts(joins: {:interfaces => :subnet})
+      @scope.load_hosts(joins: [:interfaces, :domain])
+    end
+
+    it 'should reject unacceptable joins' do
+      assert_raises(ArgumentError) { @scope.load_hosts(joins: 'a string value') }
+      assert_raises(ArgumentError) { @scope.load_hosts(joins: [:mixed, 'array']) }
+      error = assert_raises(ArgumentError) { @scope.load_hosts(joins: 7) }
+      assert_match /Value of 'joins'/, error.message
+      assert_match /load_hosts/, error.message
+      assert_match /Symbol, Hash or Array of Symbols/, error.message
+    end
+  end
+end