diff --git a/.rubocop.yml b/.rubocop.yml
index e6c5dc937..0894528da 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -441,6 +441,9 @@ Rails/FindBy:
   Exclude:
     - "config/initializers/ahoy.rb"
 
+Rails/FindByOrAssignmentMemoization:
+  Enabled: true
+
 Rails/FindEach:
   Enabled: true
 
diff --git a/app/components/admin/machine_learning/setting_component.rb b/app/components/admin/machine_learning/setting_component.rb
index e6da31334..ee218d5ee 100644
--- a/app/components/admin/machine_learning/setting_component.rb
+++ b/app/components/admin/machine_learning/setting_component.rb
@@ -8,7 +8,7 @@ class Admin::MachineLearning::SettingComponent < ApplicationComponent
   private
 
     def setting
-      @setting ||= Setting.find_by(key: "machine_learning.#{kind}")
+      @setting ||= Setting.find_by!(key: "machine_learning.#{kind}")
     end
 
     def ml_info
diff --git a/app/controllers/dashboard/successful_supports_controller.rb b/app/controllers/dashboard/successful_supports_controller.rb
index e79213e79..d42e48771 100644
--- a/app/controllers/dashboard/successful_supports_controller.rb
+++ b/app/controllers/dashboard/successful_supports_controller.rb
@@ -27,7 +27,9 @@ class Dashboard::SuccessfulSupportsController < Dashboard::BaseController
     end
 
     def successful_proposal
-      @successful_proposal ||= Proposal.find_by(id: Setting["proposals.successful_proposal_id"])
+      return @successful_proposal if defined?(@successful_proposal)
+
+      @successful_proposal = Proposal.find_by(id: Setting["proposals.successful_proposal_id"])
     end
 
     def days_diff
diff --git a/app/models/verification/management/email.rb b/app/models/verification/management/email.rb
index cb1c1bc82..311ff1a6d 100644
--- a/app/models/verification/management/email.rb
+++ b/app/models/verification/management/email.rb
@@ -11,7 +11,9 @@ class Verification::Management::Email
   delegate :username, to: :user, allow_nil: true
 
   def user
-    @user ||= User.find_by(email: email)
+    return @user if defined?(@user)
+
+    @user = User.find_by(email: email)
   end
 
   def user?