diff --git a/app/models/classification.rb b/app/models/classification.rb
index f30cb4449535..484f4b83248d 100644
--- a/app/models/classification.rb
+++ b/app/models/classification.rb
@@ -32,6 +32,7 @@ class Classification < ApplicationRecord
   scope :read_only,  -> { where(:read_only => true) }
   scope :writeable,  -> { where(:read_only => false) }
 
+  # NOTE: roots does not work (that checks :parent_id => nil)
   scope :is_category, -> { where(:parent_id => 0) }
   scope :is_entry,    -> { where.not(:parent_id => 0) }
 
diff --git a/app/models/dialog_field_importer.rb b/app/models/dialog_field_importer.rb
index 1641d7144e37..1dec6f049226 100644
--- a/app/models/dialog_field_importer.rb
+++ b/app/models/dialog_field_importer.rb
@@ -37,9 +37,9 @@ def set_category_for_tag_control(dialog_field, dialog_field_attributes)
   def adjust_category(opts)
     return nil if opts[:category_description].nil?
     category = if opts[:category_id]
-                 Category.find(opts[:category_id])
+                 Classification.is_category.find(opts[:category_id])
                elsif opts[:category_name]
-                 Category.find_by_name(opts[:category_name])
+                 Classification.is_category.find_by_name(opts[:category_name])
                end
     category.try(:description) == opts[:category_description] ? category.try(:id).to_s : nil
   end
diff --git a/app/models/dialog_field_serializer.rb b/app/models/dialog_field_serializer.rb
index 6374a7a9b8ba..72d2e6adf25a 100644
--- a/app/models/dialog_field_serializer.rb
+++ b/app/models/dialog_field_serializer.rb
@@ -22,7 +22,7 @@ def serialize(dialog_field, all_attributes = false)
     end
 
     if dialog_field.type == "DialogFieldTagControl"
-      category = Category.find_by(:id => dialog_field.category)
+      category = Classification.is_category.find_by(:id => dialog_field.category)
       if category
         dialog_field.options.merge!(:category_name => category.name, :category_description => category.description)
         dialog_field.options[:force_single_value] = dialog_field.options[:force_single_value] || category.single_value
diff --git a/spec/models/dialog_field_importer_spec.rb b/spec/models/dialog_field_importer_spec.rb
index 933ca603bd38..411e162edc83 100644
--- a/spec/models/dialog_field_importer_spec.rb
+++ b/spec/models/dialog_field_importer_spec.rb
@@ -88,8 +88,8 @@
         let(:category_description) { "best_category" }
 
         context "when the category exists by name and description" do
-          before do
-            @existing_category = Category.create!(:name => "best_category", :description => "best_category")
+          let!(:category) do
+            Classification.is_category.create!(:name => "best_category", :description => "best_category")
           end
 
           context "when the category description does not match" do
@@ -104,7 +104,7 @@
           context "when the category description matches" do
             it "uses the correct category, ignoring id" do
               dialog_field_importer.import_field(dialog_field)
-              expect(DialogFieldTagControl.first.category).to eq(@existing_category.id.to_s)
+              expect(DialogFieldTagControl.first.category).to eq(category.id.to_s)
             end
           end
         end
@@ -123,30 +123,30 @@
       end
 
       context "when the import file contains a category id a category name and a description" do
-        before do
-          @existing_category = Category.create!(:name => "best_category", :description => "best_category")
+        let!(:category) do
+          Classification.is_category.create!(:name => "best_category", :description => "best_category")
         end
         let(:options) do
           {
-            :category_id          => @existing_category.id,
-            :category_name        => @existing_category.name,
-            :category_description => @existing_category.description
+            :category_id          => category.id,
+            :category_name        => category.name,
+            :category_description => category.description
           }
         end
 
         it "uses the category id provided" do
           dialog_field_importer.import_field(dialog_field)
-          expect(DialogFieldTagControl.first.category).to eq(@existing_category.id.to_s)
+          expect(DialogFieldTagControl.first.category).to eq(category.id.to_s)
         end
       end
 
       context "when the import file contains a category id with a different description" do
-        before do
-          @existing_category = Category.create!(:name => "best_category", :description => "best_category")
+        let!(:category) do
+          Classification.is_category.create!(:name => "best_category", :description => "best_category")
         end
         let(:options) do
           {
-            :category_id          => @existing_category.id,
+            :category_id          => category.id,
             :category_description => "bad description"
           }
         end
diff --git a/spec/models/dialog_field_serializer_spec.rb b/spec/models/dialog_field_serializer_spec.rb
index 3ac470fcecb1..a567871b149f 100644
--- a/spec/models/dialog_field_serializer_spec.rb
+++ b/spec/models/dialog_field_serializer_spec.rb
@@ -132,14 +132,13 @@
       end
 
       let(:type) { "DialogFieldTagControl" }
-      let(:options) { {:category_id => "123", :force_single_value => false} }
+      let(:options) { {:category_id => category.id.to_s, :force_single_value => false} }
       let(:dynamic) { false }
       let(:category) do
-        double("Category", :name => "best category ever", :description => "best category ever", :single_value => true)
+        Classification.create!(:name => "best_category_ever", :description => "best category ever", :single_value => true)
       end
 
       before do
-        allow(Category).to receive(:find_by).with(:id => "123").and_return(category)
         allow(dialog_field).to receive(:values).and_return("values")
       end
 
@@ -152,8 +151,8 @@
                    "resource_action"         => "serialized resource action",
                    "dialog_field_responders" => dialog_field_responders,
                    "options"                 => {
-                     :category_id          => "123",
-                     :category_name        => "best category ever",
+                     :category_id          => category.id.to_s,
+                     :category_name        => "best_category_ever",
                      :category_description => "best category ever",
                      :force_single_value   => true
                    },