diff --git a/spec/models/acts_as_customizable/calculated_value_spec.rb b/spec/models/acts_as_customizable/calculated_value_spec.rb
index eca2566922c..cf8a7cb5c31 100644
--- a/spec/models/acts_as_customizable/calculated_value_spec.rb
+++ b/spec/models/acts_as_customizable/calculated_value_spec.rb
@@ -31,6 +31,8 @@
 require "spec_helper"
 
 RSpec.describe ActsAsCustomizable::CalculatedValue, with_flag: { calculated_value_project_attribute: true } do
+  using CustomFieldFormulaReferencing
+
   let(:model_class) do
     Class.new do
       include ActsAsCustomizable::CalculatedValue
@@ -47,8 +49,6 @@ RSpec.describe ActsAsCustomizable::CalculatedValue, with_flag: { calculated_valu
     allow(instance).to receive(:custom_field_values=)
   end
 
-  def ref(custom_field) = "{{cf_#{custom_field.id}}}"
-
   describe "#calculate_custom_fields" do
     context "when calling with empty array" do
       let(:custom_field_values) { [:foo] }
@@ -143,8 +143,8 @@ RSpec.describe ActsAsCustomizable::CalculatedValue, with_flag: { calculated_valu
       let(:cf_a) { build_stubbed(:integer_project_custom_field) }
       let(:cf_b) { build_stubbed(:integer_project_custom_field) }
 
-      let(:cf1) { build_stubbed(:calculated_value_project_custom_field, formula: "#{ref cf_a} + #{ref cf_b}") }
-      let(:cf2) { build_stubbed(:calculated_value_project_custom_field, formula: "#{ref cf_a} * #{ref cf_b}") }
+      let(:cf1) { build_stubbed(:calculated_value_project_custom_field, formula: "#{cf_a} + #{cf_b}") }
+      let(:cf2) { build_stubbed(:calculated_value_project_custom_field, formula: "#{cf_a} * #{cf_b}") }
 
       let(:custom_field_values) do
         {
@@ -168,7 +168,7 @@ RSpec.describe ActsAsCustomizable::CalculatedValue, with_flag: { calculated_valu
     context "when calling with custom fields referencing other calculated fields" do
       let(:cf1) { build_stubbed(:calculated_value_project_custom_field, formula: "1 + 1") }
       let(:cf2) { build_stubbed(:calculated_value_project_custom_field, formula: "1 + 2") }
-      let(:cf3) { build_stubbed(:calculated_value_project_custom_field, formula: "#{ref cf1} * #{ref cf2}") }
+      let(:cf3) { build_stubbed(:calculated_value_project_custom_field, formula: "#{cf1} * #{cf2}") }
 
       let(:custom_field_values) do
         {
@@ -206,8 +206,8 @@ RSpec.describe ActsAsCustomizable::CalculatedValue, with_flag: { calculated_valu
       let(:cf_missing) { build_stubbed(:integer_project_custom_field) }
       let(:cf_unavailable) { build_stubbed(:integer_project_custom_field) }
 
-      let(:cf_using_missing) { build_stubbed(:calculated_value_project_custom_field, formula: "1 + #{ref cf_missing}") }
-      let(:cf_using_unavailable) { build_stubbed(:calculated_value_project_custom_field, formula: "2 + #{ref cf_unavailable}") }
+      let(:cf_using_missing) { build_stubbed(:calculated_value_project_custom_field, formula: "1 + #{cf_missing}") }
+      let(:cf_using_unavailable) { build_stubbed(:calculated_value_project_custom_field, formula: "2 + #{cf_unavailable}") }
       let(:cf_other) { build_stubbed(:calculated_value_project_custom_field, formula: "1 + 2") }
 
       let(:custom_field_values) do
@@ -252,10 +252,10 @@ RSpec.describe ActsAsCustomizable::CalculatedValue, with_flag: { calculated_valu
 
       before do
         {
-          cf1 => "#{ref cf_a} * #{ref cf2}",
-          cf2 => "#{ref cf_b} * #{ref cf3}",
-          cf3 => "#{ref cf1} * #{ref cf4}",
-          cf4 => "#{ref cf_c} * #{ref cf_d}"
+          cf1 => "#{cf_a} * #{cf2}",
+          cf2 => "#{cf_b} * #{cf3}",
+          cf3 => "#{cf1} * #{cf4}",
+          cf4 => "#{cf_c} * #{cf_d}"
         }.each do |cf, formula|
           cf.formula = formula
         end
diff --git a/spec/models/custom_field/calculated_value_spec.rb b/spec/models/custom_field/calculated_value_spec.rb
index e9d73806944..d92541a9433 100644
--- a/spec/models/custom_field/calculated_value_spec.rb
+++ b/spec/models/custom_field/calculated_value_spec.rb
@@ -31,17 +31,17 @@
 require "spec_helper"
 
 RSpec.describe CustomField::CalculatedValue, with_flag: { calculated_value_project_attribute: true } do
-  subject(:custom_field) { create(:calculated_value_project_custom_field, formula: "1 + 1") }
+  using CustomFieldFormulaReferencing
 
-  def ref(custom_field) = "{{cf_#{custom_field.id}}}"
+  subject(:custom_field) { create(:calculated_value_project_custom_field, formula: "1 + 1") }
 
   describe ".with_formula_referencing", :aggregate_failures do
     shared_let(:cf_a) { create(:integer_project_custom_field, default_value: 1) }
     shared_let(:cf_b) { create(:integer_project_custom_field, default_value: 2) }
     shared_let(:cf_c) { create(:integer_project_custom_field, default_value: 3) }
 
-    shared_let(:cf1) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_a} + #{ref cf_b}") }
-    shared_let(:cf2) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_b} + #{ref cf1}") }
+    shared_let(:cf1) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_a} + #{cf_b}") }
+    shared_let(:cf2) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_b} + #{cf1}") }
 
     let(:scope) { CustomField }
 
@@ -70,10 +70,10 @@ RSpec.describe CustomField::CalculatedValue, with_flag: { calculated_value_proje
       shared_let(:cf_b) { create(:integer_project_custom_field, default_value: 2) }
       shared_let(:cf_c) { create(:integer_project_custom_field, default_value: 3) }
       shared_let(:cf_d) { create(:integer_project_custom_field, default_value: 4) }
-      shared_let(:cf1) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_a} * 2") }
-      shared_let(:cf2) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_a} + #{ref cf_b}") }
-      shared_let(:cf3) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_b} * 2") }
-      shared_let(:cf4) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_c} * 2") }
+      shared_let(:cf1) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_a} * 2") }
+      shared_let(:cf2) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_a} + #{cf_b}") }
+      shared_let(:cf3) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_b} * 2") }
+      shared_let(:cf4) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_c} * 2") }
 
       it "returns an empty array if argument is empty" do
         expect(scope.affected_calculated_fields([])).to eq([])
@@ -141,9 +141,9 @@ RSpec.describe CustomField::CalculatedValue, with_flag: { calculated_value_proje
       shared_let(:cf_c) { create(:integer_project_custom_field, default_value: 3) }
       shared_let(:cf_d) { create(:integer_project_custom_field, default_value: 4) }
 
-      shared_let(:cf1) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf_a} + #{ref cf_b}") }
-      shared_let(:cf2) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf1} * #{ref cf_c}") }
-      shared_let(:cf3) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{ref cf2} * #{ref cf_d}") }
+      shared_let(:cf1) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf_a} + #{cf_b}") }
+      shared_let(:cf2) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf1} * #{cf_c}") }
+      shared_let(:cf3) { create(:calculated_value_project_custom_field, :skip_validations, formula: "#{cf2} * #{cf_d}") }
 
       it "returns referencing fields when passing referenced constant field ids" do
         expect(scope.affected_calculated_fields([cf_a.id])).to contain_exactly(cf1, cf2, cf3)
@@ -193,9 +193,9 @@ RSpec.describe CustomField::CalculatedValue, with_flag: { calculated_value_proje
 
       before do
         {
-          cf1 => "#{ref cf_a} + #{ref cf2}",
-          cf2 => "#{ref cf_b} + #{ref cf3}",
-          cf3 => "#{ref cf_c} + #{ref cf1}"
+          cf1 => "#{cf_a} + #{cf2}",
+          cf2 => "#{cf_b} + #{cf3}",
+          cf3 => "#{cf_c} + #{cf1}"
         }.each do |cf, formula|
           cf.formula = formula
           cf.save!(validate: false)
diff --git a/spec/services/projects/set_attributes_service_spec.rb b/spec/services/projects/set_attributes_service_spec.rb
index df07cb5be9f..b85b17c4c78 100644
--- a/spec/services/projects/set_attributes_service_spec.rb
+++ b/spec/services/projects/set_attributes_service_spec.rb
@@ -322,7 +322,7 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           end
         end
 
-        def ref(custom_field) = "{{cf_#{custom_field.id}}}"
+        using CustomFieldFormulaReferencing
 
         context "when trying to explicitly set values of calculated custom fields" do
           let!(:cf_static) { create(:integer_project_custom_field, projects: [project]) }
@@ -355,12 +355,12 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           let!(:cf_calculated1) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_static} * 7")
+                   formula: "#{cf_static} * 7")
           end
           let!(:cf_calculated2) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_calculated1} * 11")
+                   formula: "#{cf_calculated1} * 11")
           end
 
           let(:call_attributes) do
@@ -391,12 +391,12 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           let!(:cf_calculated1) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_static} * 7")
+                   formula: "#{cf_static} * 7")
           end
           let!(:cf_calculated2) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_calculated1} * 11")
+                   formula: "#{cf_calculated1} * 11")
           end
 
           let(:call_attributes) do
@@ -428,15 +428,15 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           let!(:cf_c) { create(:integer_project_custom_field, projects: [project]) }
           let!(:cf_calculated1) do
             create(:calculated_value_project_custom_field, :skip_validations,
-                   projects: [project], formula: "#{ref cf_a} * 7")
+                   projects: [project], formula: "#{cf_a} * 7")
           end
           let!(:cf_calculated2) do
             create(:calculated_value_project_custom_field, :skip_validations,
-                   projects: [project], formula: "#{ref cf_b} * 11")
+                   projects: [project], formula: "#{cf_b} * 11")
           end
           let!(:cf_calculated3) do
             create(:calculated_value_project_custom_field, :skip_validations,
-                   projects: [project], formula: "#{ref cf_c} * 13")
+                   projects: [project], formula: "#{cf_c} * 13")
           end
 
           let(:call_attributes) do
@@ -474,16 +474,16 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           let!(:cf_calculated1) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_static} * 7")
+                   formula: "#{cf_static} * 7")
           end
           let!(:cf_calculated2) do
             create(:calculated_value_project_custom_field, :skip_validations,
-                   formula: "#{ref cf_calculated1} * 11")
+                   formula: "#{cf_calculated1} * 11")
           end
           let!(:cf_calculated3) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_calculated2} * 13")
+                   formula: "#{cf_calculated2} * 13")
           end
 
           let(:call_attributes) do
@@ -522,17 +522,17 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           let!(:cf_calculated1) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_static} * 7")
+                   formula: "#{cf_static} * 7")
           end
           let!(:cf_calculated2) do
             create(:calculated_value_project_custom_field, :skip_validations, :admin_only,
                    projects: [project],
-                   formula: "#{ref cf_calculated1} * 11")
+                   formula: "#{cf_calculated1} * 11")
           end
           let!(:cf_calculated3) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_calculated2} * 13")
+                   formula: "#{cf_calculated2} * 13")
           end
 
           let(:call_attributes) do
@@ -565,7 +565,7 @@ RSpec.describe Projects::SetAttributesService, type: :model do
           let!(:cf_calculated) do
             create(:calculated_value_project_custom_field, :skip_validations,
                    projects: [project],
-                   formula: "#{ref cf_static} * #{ref cf_referenced}")
+                   formula: "#{cf_static} * #{cf_referenced}")
           end
 
           let(:call_attributes) do
@@ -632,7 +632,7 @@ RSpec.describe Projects::SetAttributesService, type: :model do
             let!(:cf_referenced) do
               create(:calculated_value_project_custom_field, :skip_validations, :admin_only,
                      projects: [project],
-                     formula: "21 * #{ref cf_referenced1}")
+                     formula: "21 * #{cf_referenced1}")
             end
 
             before do
diff --git a/spec/support/custom_field_formula_referencing.rb b/spec/support/custom_field_formula_referencing.rb
new file mode 100644
index 00000000000..216a5d24634
--- /dev/null
+++ b/spec/support/custom_field_formula_referencing.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+# Allows cleaner building of calculated value formulas in specs:
+#
+#     using CustomFieldFormulaReferencing
+#
+#     create(:calculated_value_project_custom_field, formula: "#{cf_1} * #{cf_2} + #{cf_3}")
+module CustomFieldFormulaReferencing
+  refine CustomField do
+    def to_s
+      "{{cf_#{id}}}"
+    end
+  end
+end