diff --git a/app/models/custom_comment.rb b/app/models/custom_comment.rb
index 469a73b29b4..80ef1861541 100644
--- a/app/models/custom_comment.rb
+++ b/app/models/custom_comment.rb
@@ -37,19 +37,10 @@ class CustomComment < ApplicationRecord
   validates :custom_field, presence: true, uniqueness: { scope: :customized }
   validates :customized, presence: true
 
-  after_create :activate_custom_field_in_customized_project, if: -> { customized.is_a?(Project) }
-
   private
 
   # to not deal with it in Journals::CreateService::CustomComment#changes_sql
   def normalize_newlines
     self.text = text.gsub(/\r\n?/, "\n") if text
   end
-
-  def activate_custom_field_in_customized_project
-    return if custom_field.is_for_all?
-    return if customized&.project_custom_fields&.include?(custom_field)
-
-    customized.project_custom_fields << custom_field
-  end
 end
diff --git a/spec/models/custom_comment_spec.rb b/spec/models/custom_comment_spec.rb
index c96b1397bc6..59ba738c102 100644
--- a/spec/models/custom_comment_spec.rb
+++ b/spec/models/custom_comment_spec.rb
@@ -55,28 +55,4 @@ RSpec.describe CustomComment do
       expect(comment.reload.text).to eq("Line 1\nLine 2\nLine 3\nLine 4")
     end
   end
-
-  describe "auto enabling custom field for project" do
-    let(:project) { create(:project) }
-
-    context "when custom field is not marked for all" do
-      let(:custom_field) { create(:project_custom_field) }
-
-      it "auto enables it for project" do
-        create(:custom_comment, custom_field:, customized: project)
-
-        expect(project.project_custom_fields).to eq([custom_field])
-      end
-    end
-
-    context "when field is marked for all" do
-      let(:custom_field) { create(:project_custom_field, :is_for_all) }
-
-      it "doesn't auto enable it for project" do
-        create(:custom_comment, custom_field:, customized: project)
-
-        expect(project.project_custom_fields).to eq([])
-      end
-    end
-  end
 end
diff --git a/spec/models/projects/project_acts_as_journalized_spec.rb b/spec/models/projects/project_acts_as_journalized_spec.rb
index b34c78a06d4..92b361ad06d 100644
--- a/spec/models/projects/project_acts_as_journalized_spec.rb
+++ b/spec/models/projects/project_acts_as_journalized_spec.rb
@@ -230,7 +230,7 @@ RSpec.describe Project, "acts_as_journalized" do
   end
 
   describe "custom comments" do
-    shared_let(:custom_field) { create(:string_project_custom_field, :has_comment) }
+    let!(:custom_field) { create(:string_project_custom_field, :has_comment, projects: [project]) }
     let(:custom_comment_key) { "custom_comment_#{custom_field.id}" }
     let(:custom_comment_text) { "some descriptive comment" }
     let(:modified_custom_comment_text) { "a more descriptive comment" }