diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 8b95d8ee4..20a57954d 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -718,25 +718,6 @@ Rails/Delegate:
     - 'lib/mongoid/findable.rb'
     - 'lib/mongoid/scopable.rb'
 
-# Offense count: 91
-# Configuration parameters: Include.
-# Include: spec/**/*.rb, test/**/*.rb
-Rails/I18nLocaleAssignment:
-  Exclude:
-    - 'spec/integration/i18n_fallbacks_spec.rb'
-    - 'spec/mongoid/contextual/memory_spec.rb'
-    - 'spec/mongoid/contextual/mongo_spec.rb'
-    - 'spec/mongoid/copyable_spec.rb'
-    - 'spec/mongoid/criteria/queryable/options_spec.rb'
-    - 'spec/mongoid/criteria/queryable/selector_spec.rb'
-    - 'spec/mongoid/criteria_projection_spec.rb'
-    - 'spec/mongoid/criteria_spec.rb'
-    - 'spec/mongoid/fields/localized_spec.rb'
-    - 'spec/mongoid/fields_spec.rb'
-    - 'spec/mongoid/persistable/updatable_spec.rb'
-    - 'spec/mongoid/validatable/uniqueness_spec.rb'
-    - 'spec/support/macros.rb'
-
 # Offense count: 133
 # Configuration parameters: ForbiddenMethods, AllowedMethods.
 # ForbiddenMethods: decrement!, decrement_counter, increment!, increment_counter, insert, insert!, insert_all, insert_all!, toggle!, touch, touch_all, update_all, update_attribute, update_column, update_columns, update_counters, upsert, upsert_all
diff --git a/spec/integration/i18n_fallbacks_spec.rb b/spec/integration/i18n_fallbacks_spec.rb
index 3d9b6b807..6a3fb8d58 100644
--- a/spec/integration/i18n_fallbacks_spec.rb
+++ b/spec/integration/i18n_fallbacks_spec.rb
@@ -8,38 +8,37 @@
   context 'when fallbacks are enabled with a locale list' do
     with_default_i18n_configs
 
-    before do
-      I18n.fallbacks[:de] = [:en]
-    end
+    before { I18n.fallbacks[:de] = [:en] }
+
+    let(:product) { Product.new }
 
     context 'when translation is present in active locale' do
-      it 'uses active locale' do
-        product = Product.new
-        I18n.locale = :de
+      around { |example| I18n.with_locale(:de) { example.run } }
+
+      before do
         product.description = 'Marvelous in German'
-        I18n.locale = :en
-        product.description = 'Marvelous!'
-        I18n.locale = :de
+        I18n.with_locale(:en) { product.description = 'Marvelous!' }
+      end
+
+      it 'uses active locale' do
         expect(product.description).to eq('Marvelous in German')
       end
     end
 
     context 'when translation is missing in active locale and present in fallback locale' do
+      around { |example| I18n.with_locale(:de) { example.run } }
+      before { I18n.with_locale(:en) { product.description = 'Marvelous!' } }
+
       it 'falls back on default locale' do
-        product = Product.new
-        I18n.locale = :en
-        product.description = 'Marvelous!'
-        I18n.locale = :de
         expect(product.description).to eq('Marvelous!')
       end
     end
 
     context 'when translation is missing in all locales' do
+      around { |example| I18n.with_locale(:ru) { example.run } }
+      before { I18n.with_locale(:en) { product.description = 'Marvelous!' } }
+
       it 'returns nil' do
-        product = Product.new
-        I18n.locale = :en
-        product.description = 'Marvelous!'
-        I18n.locale = :ru
         expect(product.description).to be_nil
       end
     end
diff --git a/spec/mongoid/contextual/memory_spec.rb b/spec/mongoid/contextual/memory_spec.rb
index 62749d432..d232a645e 100644
--- a/spec/mongoid/contextual/memory_spec.rb
+++ b/spec/mongoid/contextual/memory_spec.rb
@@ -459,52 +459,55 @@
     context 'when getting a localized field' do
       with_default_i18n_configs
 
-      before do
-        I18n.locale = :en
-        d = Dictionary.create!(description: 'english-text')
-        I18n.locale = :de
-        d.description = 'deutsch-text'
-        d.save!
-      end
-
       let(:criteria) do
         Dictionary.all.tap do |crit|
           crit.documents = [Dictionary.first]
         end
       end
 
-      context 'when getting the field without _translations' do
-        it 'gets the demongoized localized field' do
-          expect(context.distinct(:description)).to eq(['deutsch-text'])
-        end
-      end
+      context 'without fallbacks' do
+        let(:dictionary) { Dictionary.new }
 
-      context 'when getting the field with _translations' do
+        around { |example| I18n.with_locale(:de) { example.run } }
 
-        it 'gets the full hash' do
-          expect(context.distinct(:description_translations)).to eq([{ 'de' => 'deutsch-text', 'en' => 'english-text' }])
+        before do
+          I18n.with_locale(:en) { dictionary.description = 'english-text' }
+          dictionary.description = 'deutsch-text'
+          dictionary.save!
         end
-      end
-
-      context 'when plucking a specific locale' do
 
-        let(:distinct) do
-          context.distinct(:'description.de')
+        context 'when getting the field without _translations' do
+          it 'gets the demongoized localized field' do
+            expect(context.distinct(:description)).to eq(['deutsch-text'])
+          end
         end
 
-        it 'returns the specific translation' do
-          expect(distinct).to eq(['deutsch-text'])
+        context 'when getting the field with _translations' do
+          it 'gets the full hash' do
+            expect(context.distinct(:description_translations)).to eq([{ 'de' => 'deutsch-text', 'en' => 'english-text' }])
+          end
         end
-      end
 
-      context 'when plucking a specific locale from _translations field' do
+        context 'when plucking a specific locale' do
 
-        let(:distinct) do
-          context.distinct(:'description_translations.de')
+          let(:distinct) do
+            context.distinct(:'description.de')
+          end
+
+          it 'returns the specific translation' do
+            expect(distinct).to eq(['deutsch-text'])
+          end
         end
 
-        it 'returns the specific translations' do
-          expect(distinct).to eq(['deutsch-text'])
+        context 'when plucking a specific locale from _translations field' do
+
+          let(:distinct) do
+            context.distinct(:'description_translations.de')
+          end
+
+          it 'returns the specific translations' do
+            expect(distinct).to eq(['deutsch-text'])
+          end
         end
       end
 
@@ -512,18 +515,18 @@
         with_i18n_fallbacks
         with_default_i18n_configs
 
-        before do
-          I18n.fallbacks[:he] = [:en]
-        end
-
         let(:distinct) do
           context.distinct(:description).first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
+        before do
+          I18n.fallbacks[:he] = [:en]
+          I18n.with_locale(:en) { Dictionary.create!(description: 'english-text') }
+        end
+
         it 'correctly uses the fallback' do
-          I18n.locale = :en
-          Dictionary.create!(description: 'english-text')
-          I18n.locale = :he
           expect(distinct).to eq 'english-text'
         end
       end
@@ -533,10 +536,8 @@
 
         let(:person) do
           p = Passport.new
-          I18n.locale = :en
-          p.name = 'Neil'
-          I18n.locale = :he
-          p.name = 'Nissim'
+          I18n.with_locale(:en) { p.name = 'Neil' }
+          I18n.with_locale(:he) { p.name = 'Nissim' }
 
           Person.create!(passport: p, employer_id: 12345)
         end
@@ -559,6 +560,8 @@
           context.distinct('pass.name_translations.en').first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
         it 'returns the translation for the current locale' do
           expect(distinct).to eq('Nissim')
         end
@@ -1624,66 +1627,70 @@
     context 'when plucking a localized field' do
       with_default_i18n_configs
 
-      before do
-        I18n.locale = :en
-        d = Dictionary.create!(description: 'english-text')
-        I18n.locale = :de
-        d.description = 'deutsch-text'
-        d.save!
-      end
-
       let(:criteria) do
         Dictionary.all.tap do |crit|
           crit.documents = [Dictionary.first]
         end
       end
 
-      context 'when plucking the entire field' do
+      context 'without fallbacks' do
+        let(:dictionary) { Dictionary.new }
 
-        let(:plucked) do
-          context.pluck(:description)
-        end
+        around { |example| I18n.with_locale(:de) { example.run } }
 
-        let(:plucked_translations) do
-          context.pluck(:description_translations)
+        before do
+          I18n.with_locale(:en) { dictionary.description = 'english-text' }
+          dictionary.description = 'deutsch-text'
+          dictionary.save!
         end
 
-        let(:plucked_translations_both) do
-          context.pluck(:description_translations, :description)
-        end
+        context 'when plucking the entire field' do
 
-        it 'returns the demongoized translations' do
-          expect(plucked.first).to eq('deutsch-text')
-        end
+          let(:plucked) do
+            context.pluck(:description)
+          end
 
-        it 'returns the full translations hash to _translations' do
-          expect(plucked_translations.first).to eq({ 'de' => 'deutsch-text', 'en' => 'english-text' })
-        end
+          let(:plucked_translations) do
+            context.pluck(:description_translations)
+          end
 
-        it 'returns both' do
-          expect(plucked_translations_both.first).to eq([{ 'de' => 'deutsch-text', 'en' => 'english-text' }, 'deutsch-text'])
-        end
-      end
+          let(:plucked_translations_both) do
+            context.pluck(:description_translations, :description)
+          end
 
-      context 'when plucking a specific locale' do
+          it 'returns the demongoized translations' do
+            expect(plucked.first).to eq('deutsch-text')
+          end
 
-        let(:plucked) do
-          context.pluck(:'description.de')
-        end
+          it 'returns the full translations hash to _translations' do
+            expect(plucked_translations.first).to eq({ 'de' => 'deutsch-text', 'en' => 'english-text' })
+          end
 
-        it 'returns the specific translations' do
-          expect(plucked.first).to eq('deutsch-text')
+          it 'returns both' do
+            expect(plucked_translations_both.first).to eq([{ 'de' => 'deutsch-text', 'en' => 'english-text' }, 'deutsch-text'])
+          end
         end
-      end
 
-      context 'when plucking a specific locale from _translations field' do
+        context 'when plucking a specific locale' do
 
-        let(:plucked) do
-          context.pluck(:'description_translations.de')
+          let(:plucked) do
+            context.pluck(:'description.de')
+          end
+
+          it 'returns the specific translations' do
+            expect(plucked.first).to eq('deutsch-text')
+          end
         end
 
-        it 'returns the specific translations' do
-          expect(plucked.first).to eq('deutsch-text')
+        context 'when plucking a specific locale from _translations field' do
+
+          let(:plucked) do
+            context.pluck(:'description_translations.de')
+          end
+
+          it 'returns the specific translations' do
+            expect(plucked.first).to eq('deutsch-text')
+          end
         end
       end
 
@@ -1691,18 +1698,18 @@
         with_i18n_fallbacks
         with_default_i18n_configs
 
-        before do
-          I18n.fallbacks[:he] = [:en]
-        end
-
         let(:plucked) do
           context.pluck(:description).first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
+        before do
+          I18n.fallbacks[:he] = [:en]
+          I18n.with_locale(:en) { Dictionary.create!(description: 'english-text') }
+        end
+
         it 'correctly uses the fallback' do
-          I18n.locale = :en
-          Dictionary.create!(description: 'english-text')
-          I18n.locale = :he
           expect(plucked).to eq 'english-text'
         end
       end
@@ -1710,15 +1717,7 @@
       context 'when the localized field is embedded' do
         with_default_i18n_configs
 
-        before do
-          p = Passport.new
-          I18n.locale = :en
-          p.name = 'Neil'
-          I18n.locale = :he
-          p.name = 'Nissim'
-
-          Person.create!(passport: p, employer_id: 12345)
-        end
+        let(:passport) { Passport.new }
 
         let(:plucked) do
           Person.where(employer_id: 12345).pluck('pass.name').first
@@ -1732,6 +1731,14 @@
           Person.where(employer_id: 12345).pluck('pass.name_translations.en').first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
+        before do
+          I18n.with_locale(:en) { passport.name = 'Neil' }
+          passport.name = 'Nissim'
+          Person.create!(passport: passport, employer_id: 12345)
+        end
+
         it 'returns the translation for the current locale' do
           expect(plucked).to eq('Nissim')
         end
@@ -2093,18 +2100,20 @@
         let(:d3) { Dictionary.new(description: 'en1') }
         let(:d4) { Dictionary.new(description: 'en2') }
 
+        around { |example| I18n.with_locale(:en) { example.run } }
+
         before do
-          I18n.locale = :en
           d1
           d2
           d3
           d4
-          I18n.locale = :de
-          d1.description = 'de1'
-          d2.description = 'de1'
-          d3.description = 'de2'
-          d4.description = 'de3'
-          I18n.locale = :en
+
+          I18n.with_locale(:de) do
+            d1.description = 'de1'
+            d2.description = 'de1'
+            d3.description = 'de2'
+            d4.description = 'de3'
+          end
         end
 
         context 'when getting the demongoized field' do
@@ -2188,20 +2197,22 @@
       let(:address2a) { Address.new(name: 'en1') }
       let(:address2b) { Address.new(name: 'en3') }
 
+      around { |example| I18n.with_locale(:en) { example.run } }
+
       before do
-        I18n.locale = :en
         address1a
         address1b
         address2a
         address2b
-        I18n.locale = :de
-        address1a.name = 'de1'
-        address1b.name = 'de2'
-        address2a.name = 'de1'
-        address2b.name = 'de3'
-        person1
-        person2
-        I18n.locale = :en
+
+        I18n.with_locale(:de) do
+          address1a.name = 'de1'
+          address1b.name = 'de2'
+          address2a.name = 'de1'
+          address2b.name = 'de3'
+          person1
+          person2
+        end
       end
 
       context 'when getting the demongoized field' do
diff --git a/spec/mongoid/contextual/mongo_spec.rb b/spec/mongoid/contextual/mongo_spec.rb
index ed5447aae..07ee7d411 100644
--- a/spec/mongoid/contextual/mongo_spec.rb
+++ b/spec/mongoid/contextual/mongo_spec.rb
@@ -565,14 +565,6 @@
     context 'when getting a localized field' do
       with_default_i18n_configs
 
-      before do
-        I18n.locale = :en
-        d = Dictionary.create!(description: 'english-text')
-        I18n.locale = :de
-        d.description = 'deutsch-text'
-        d.save!
-      end
-
       let(:criteria) do
         Dictionary.criteria
       end
@@ -581,6 +573,16 @@
         described_class.new(criteria)
       end
 
+      let(:dictionary) { Dictionary.new }
+
+      around { |example| I18n.with_locale(:de) { example.run } }
+
+      before do
+        I18n.with_locale(:en) { dictionary.description = 'english-text' }
+        dictionary.description = 'deutsch-text'
+        dictionary.save!
+      end
+
       context 'when getting the field without _translations' do
         it 'gets the demongoized localized field' do
           expect(context.distinct(:description)).to eq(['deutsch-text'])
@@ -619,18 +621,16 @@
         with_i18n_fallbacks
         with_default_i18n_configs
 
+        let(:distinct) { context.distinct(:description).first }
+
+        around { |example| I18n.with_locale(:he) { example.run } }
+
         before do
           I18n.fallbacks[:he] = [:en]
-        end
-
-        let(:distinct) do
-          context.distinct(:description).first
+          I18n.with_locale(:en) { Dictionary.create!(description: 'english-text') }
         end
 
         it 'correctly uses the fallback' do
-          I18n.locale = :en
-          Dictionary.create!(description: 'english-text')
-          I18n.locale = :he
           expect(distinct).to eq('english-text')
         end
       end
@@ -638,15 +638,7 @@
       context 'when the localized field is embedded' do
         with_default_i18n_configs
 
-        before do
-          p = Passport.new
-          I18n.locale = :en
-          p.name = 'Neil'
-          I18n.locale = :he
-          p.name = 'Nissim'
-
-          Person.create!(passport: p, employer_id: 12345)
-        end
+        let(:passport) { Passport.new }
 
         let(:criteria) do
           Person.where(employer_id: 12345)
@@ -668,6 +660,14 @@
           context.distinct('pass.name_translations.en').first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
+        before do
+          I18n.with_locale(:en) { passport.name = 'Neil' }
+          passport.name = 'Nissim'
+          Person.create!(passport: passport, employer_id: 12345)
+        end
+
         it 'returns the translation for the current locale' do
           expect(distinct).to eq('Nissim')
         end
@@ -754,22 +754,24 @@
       context 'when tallying a localized field' do
         with_default_i18n_configs
 
+        around { |example| I18n.with_locale(:en) { example.run } }
+
         before do
-          I18n.locale = :en
           d1 = Dictionary.create!(description: 'en1')
           d2 = Dictionary.create!(description: 'en1')
           d3 = Dictionary.create!(description: 'en1')
           d4 = Dictionary.create!(description: 'en2')
-          I18n.locale = :de
-          d1.description = 'de1'
-          d2.description = 'de1'
-          d3.description = 'de2'
-          d4.description = 'de3'
-          d1.save!
-          d2.save!
-          d3.save!
-          d4.save!
-          I18n.locale = :en
+
+          I18n.with_locale(:de) do
+            d1.description = 'de1'
+            d2.description = 'de1'
+            d3.description = 'de2'
+            d4.description = 'de3'
+            d1.save!
+            d2.save!
+            d3.save!
+            d4.save!
+          end
         end
 
         context 'when getting the demongoized field' do
@@ -878,20 +880,22 @@
     context 'when tallying an embedded localized field' do
       with_default_i18n_configs
 
+      around { |example| I18n.with_locale(:en) { example.run } }
+
       before do
-        I18n.locale = :en
         address1a = Address.new(name: 'en1')
         address1b = Address.new(name: 'en2')
         address2a = Address.new(name: 'en1')
         address2b = Address.new(name: 'en3')
-        I18n.locale = :de
-        address1a.name = 'de1'
-        address1b.name = 'de2'
-        address2a.name = 'de1'
-        address2b.name = 'de3'
-        Person.create!(addresses: [address1a, address1b])
-        Person.create!(addresses: [address2a, address2b])
-        I18n.locale = :en
+
+        I18n.with_locale(:de) do
+          address1a.name = 'de1'
+          address1b.name = 'de2'
+          address2a.name = 'de1'
+          address2b.name = 'de3'
+          Person.create!(addresses: [address1a, address1b])
+          Person.create!(addresses: [address2a, address2b])
+        end
       end
 
       context 'when getting the demongoized field' do
diff --git a/spec/mongoid/copyable_spec.rb b/spec/mongoid/copyable_spec.rb
index 726b83351..99a0575e9 100644
--- a/spec/mongoid/copyable_spec.rb
+++ b/spec/mongoid/copyable_spec.rb
@@ -166,10 +166,11 @@
         with_default_i18n_configs
 
         before do
-          I18n.locale = 'pt_BR'
-          person.desc = 'descrição'
-          person.addresses.first.name = 'descrição'
-          person.save!
+          I18n.with_locale(:pt_BR) do
+            person.desc = 'descrição'
+            person.addresses.first.name = 'descrição'
+            person.save!
+          end
         end
 
         let!(:from_db) do
@@ -180,29 +181,38 @@
           from_db.send(method)
         end
 
-        it 'sets the pt_BR version' do
-          I18n.locale = 'pt_BR'
-          expect(copy.desc).to eq('descrição')
-        end
+        context 'with pt_BR locale' do
+          around { |example| I18n.with_locale(:pt_BR) { example.run } }
 
-        it 'sets the english version' do
-          I18n.locale = :en
-          expect(copy.desc).to eq('description')
-        end
+          it 'sets the pt_BR version' do
+            expect(copy.desc).to eq('descrição')
+          end
 
-        it 'sets to nil an nonexistent lang' do
-          I18n.locale = :fr
-          expect(copy.desc).to be_nil
+          it 'sets embedded translations' do
+            expect(copy.addresses.first.name).to eq('descrição')
+          end
         end
 
-        it 'sets embedded translations' do
-          I18n.locale = 'pt_BR'
-          expect(copy.addresses.first.name).to eq('descrição')
+        context 'with en locale' do
+          around { |example| I18n.with_locale(:en) { example.run } }
+
+          it 'sets the english version' do
+            expect(copy.desc).to eq('description')
+          end
+
+          it 'sets embedded english version' do
+            I18n.with_locale(:en) do
+              expect(copy.addresses.first.name).to eq('Bond')
+            end
+          end
         end
 
-        it 'sets embedded english version' do
-          I18n.locale = :en
-          expect(copy.addresses.first.name).to eq('Bond')
+        context 'with fr (nonexistent) locale' do
+          around { |example| I18n.with_locale(:fr) { example.run } }
+
+          it 'sets the fallback (en) version' do
+            expect(copy.desc).to eq('description')
+          end
         end
       end
 
@@ -213,8 +223,9 @@
           person.addresses.build({ shipping_name: 'Title' }, ShipmentAddress)
         end
 
+        around { |example| I18n.with_locale(:pt_BR) { example.run } }
+
         before do
-          I18n.locale = 'pt_BR'
           person.addresses.type(ShipmentAddress).each { |address| address.shipping_name = 'Título' }
           person.save!
         end
@@ -228,7 +239,6 @@
         end
 
         it 'sets embedded translations' do
-          I18n.locale = 'pt_BR'
           copy.addresses.type(ShipmentAddress).each do |address|
             expect(address.shipping_name).to eq('Título')
           end
diff --git a/spec/mongoid/criteria/queryable/options_spec.rb b/spec/mongoid/criteria/queryable/options_spec.rb
index eb7134e30..ec5e87df1 100644
--- a/spec/mongoid/criteria/queryable/options_spec.rb
+++ b/spec/mongoid/criteria/queryable/options_spec.rb
@@ -238,9 +238,7 @@ def localized?
             described_class.new({}, { 'key' => Field.new })
           end
 
-          before do
-            I18n.locale = :de
-          end
+          around { |example| I18n.with_locale(:de) { example.run } }
 
           context 'when the criterion is simple' do
 
diff --git a/spec/mongoid/criteria/queryable/selector_spec.rb b/spec/mongoid/criteria/queryable/selector_spec.rb
index 9e54f9d4c..36474cfdc 100644
--- a/spec/mongoid/criteria/queryable/selector_spec.rb
+++ b/spec/mongoid/criteria/queryable/selector_spec.rb
@@ -797,9 +797,7 @@ def localized?
             described_class.new({}, { 'key' => Field.new })
           end
 
-          before do
-            I18n.locale = :de
-          end
+          around { |example| I18n.with_locale(:de) { example.run } }
 
           context 'when the criterion is simple' do
 
diff --git a/spec/mongoid/criteria_projection_spec.rb b/spec/mongoid/criteria_projection_spec.rb
index 1a6b2dc93..b74882774 100644
--- a/spec/mongoid/criteria_projection_spec.rb
+++ b/spec/mongoid/criteria_projection_spec.rb
@@ -156,82 +156,93 @@
     context 'when the field is localized' do
       with_default_i18n_configs
 
+      let(:dictionary) { Dictionary.new }
+
+      around { |example| I18n.with_locale(:de) { example.run } }
+
       before do
-        I18n.locale = :en
-        d = Dictionary.create!(description: 'english-text')
-        I18n.locale = :de
-        d.description = 'deutsch-text'
-        d.save!
+        I18n.with_locale(:en) { dictionary.description = 'english-text' }
+        dictionary.description = 'deutsch-text'
+        dictionary.save!
       end
 
       context 'when entire field is included' do
 
-        let(:dictionary) do
+        let(:dict_descr) do
           Dictionary.only(:description).first
         end
 
         it 'loads all translations' do
-          expect(dictionary.description_translations.keys).to include('de', 'en')
+          expect(dict_descr.description_translations.keys).to include('de', 'en')
         end
 
         it 'returns the field value for the current locale' do
-          I18n.locale = :en
-          expect(dictionary.description).to eq('english-text')
-          I18n.locale = :de
-          expect(dictionary.description).to eq('deutsch-text')
+          expect(dict_descr.description).to eq('deutsch-text')
+        end
+
+        it 'returns the field value for the en locale' do
+          I18n.with_locale(:en) do
+            expect(dict_descr.description).to eq('english-text')
+          end
         end
       end
 
       context 'when a specific locale is included' do
 
-        let(:dictionary) do
+        let(:dict_descr_de) do
           Dictionary.only(:'description.de').first
         end
 
         it 'loads translations only for the included locale' do
-          expect(dictionary.description_translations.keys).to include('de')
-          expect(dictionary.description_translations.keys).to_not include('en')
+          expect(dict_descr_de.description_translations.keys).to include('de')
+          expect(dict_descr_de.description_translations.keys).to_not include('en')
         end
 
         it 'returns the field value for the included locale' do
-          I18n.locale = :en
-          expect(dictionary.description).to be_nil
-          I18n.locale = :de
-          expect(dictionary.description).to eq('deutsch-text')
+          expect(dict_descr_de.description).to eq('deutsch-text')
+        end
+
+        it 'doesnt return the field value for the excluded locale' do
+          I18n.with_locale(:en) do
+            expect(dict_descr_de.description).to be_nil
+          end
         end
       end
 
       context 'when entire field is excluded' do
 
-        let(:dictionary) do
+        let(:dict_wo_descr) do
           Dictionary.without(:description).first
         end
 
         it 'does not load all translations' do
-          expect(dictionary.description_translations.keys).to_not include('de', 'en')
+          expect(dict_wo_descr.description_translations.keys).to_not include('de', 'en')
         end
 
         it 'raises an Mongoid::Errors::AttributeNotLoaded when attempting to access the field' do
-          expect { dictionary.description }.to raise_error Mongoid::Errors::AttributeNotLoaded
+          expect { dict_wo_descr.description }.to raise_error Mongoid::Errors::AttributeNotLoaded
         end
       end
 
       context 'when a specific locale is excluded' do
 
-        let(:dictionary) do
+        let(:dict_wo_descr_de) do
           Dictionary.without(:'description.de').first
         end
 
         it 'does not load excluded translations' do
-          expect(dictionary.description_translations.keys).to_not include('de')
-          expect(dictionary.description_translations.keys).to include('en')
+          expect(dict_wo_descr_de.description_translations.keys).to_not include('de')
+          expect(dict_wo_descr_de.description_translations.keys).to include('en')
         end
 
         it 'returns nil for excluded translations' do
-          I18n.locale = :en
-          expect(dictionary.description).to eq('english-text')
-          I18n.locale = :de
-          expect(dictionary.description).to be_nil
+          expect(dict_wo_descr_de.description).to be_nil
+        end
+
+        it 'returns the field value for included translations' do
+          I18n.with_locale(:en) do
+            expect(dict_wo_descr_de.description).to eq('english-text')
+          end
         end
       end
     end
diff --git a/spec/mongoid/criteria_spec.rb b/spec/mongoid/criteria_spec.rb
index dc9efc4bc..df4622640 100644
--- a/spec/mongoid/criteria_spec.rb
+++ b/spec/mongoid/criteria_spec.rb
@@ -1879,12 +1879,14 @@
     context 'when plucking a localized field' do
       with_default_i18n_configs
 
+      let(:dictionary) { Dictionary.new }
+
+      around { |example| I18n.with_locale(:de) { example.run } }
+
       before do
-        I18n.locale = :en
-        d = Dictionary.create!(description: 'english-text')
-        I18n.locale = :de
-        d.description = 'deutsch-text'
-        d.save!
+        I18n.with_locale(:en) { dictionary.description = 'english-text' }
+        dictionary.description = 'deutsch-text'
+        dictionary.save!
       end
 
       context 'when plucking the entire field' do
@@ -1935,37 +1937,10 @@
         end
       end
 
-      context 'when fallbacks are enabled with a locale list' do
-        with_i18n_fallbacks
-
-        before do
-          I18n.fallbacks[:he] = [:en]
-        end
-
-        let(:plucked) do
-          Dictionary.all.pluck(:description).first
-        end
-
-        it 'correctly uses the fallback' do
-          I18n.locale = :en
-          Dictionary.create!(description: 'english-text')
-          I18n.locale = :he
-          expect(plucked).to eq('english-text')
-        end
-      end
-
       context 'when the localized field is embedded' do
         with_default_i18n_configs
 
-        before do
-          p = Passport.new
-          I18n.locale = :en
-          p.name = 'Neil'
-          I18n.locale = :he
-          p.name = 'Nissim'
-
-          Person.create!(passport: p, employer_id: 12345)
-        end
+        let(:passport) { Passport.new }
 
         let(:plucked) do
           Person.where(employer_id: 12345).pluck('pass.name').first
@@ -1979,6 +1954,15 @@
           Person.where(employer_id: 12345).pluck('pass.name_translations.en').first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
+        before do
+          I18n.with_locale(:en) { passport.name = 'Neil' }
+          passport.name = 'Nissim'
+
+          Person.create!(passport: passport, employer_id: 12345)
+        end
+
         it 'returns the translation for the current locale' do
           expect(plucked).to eq('Nissim')
         end
@@ -1993,6 +1977,31 @@
       end
     end
 
+    context 'when plucking a localized field with fallbacks' do
+      with_default_i18n_configs
+
+      around { |example| I18n.with_locale(:he) { example.run } }
+
+      before do
+        I18n.fallbacks[:he] = [:en]
+        I18n.with_locale(:en) do
+          Dictionary.create!(description: 'english-text')
+        end
+      end
+
+      context 'when fallbacks are enabled with a locale list' do
+        with_i18n_fallbacks
+
+        let(:plucked) do
+          Dictionary.all.pluck(:description).first
+        end
+
+        it 'correctly uses the fallback' do
+          expect(plucked).to eq('english-text')
+        end
+      end
+    end
+
     context 'when plucking a field to be demongoized' do
 
       let(:plucked) do
@@ -2286,16 +2295,14 @@
 
     context 'when plucking a localized field' do
 
-      before do
-        I18n.locale = :en
-        d = Dictionary.create!(description: 'english-text')
-        I18n.locale = :de
-        d.description = 'deutsch-text'
-        d.save!
-      end
+      let(:dictionary) { Dictionary.new }
 
-      after do
-        I18n.locale = :en
+      around { |example| I18n.with_locale(:de) { example.run } }
+
+      before do
+        I18n.with_locale(:en) { dictionary.description = 'english-text' }
+        dictionary.description = 'deutsch-text'
+        dictionary.save!
       end
 
       context 'when plucking the entire field' do
@@ -2350,39 +2357,34 @@
           expect(plucked.first).to eq('deutsch-text')
         end
       end
+    end
 
+    context 'when plucking a localized field with fallbacks' do
       context 'when fallbacks are enabled with a locale list' do
         with_i18n_fallbacks
 
-        around(:all) do |example|
+        let(:plucked) do
+          Dictionary.all.pluck_each(:description).first
+        end
+
+        around do |example|
           prev_fallbacks = I18n.fallbacks.dup
           I18n.fallbacks[:he] = [:en]
-          example.run
+          I18n.with_locale(:he) { example.run }
           I18n.fallbacks = prev_fallbacks
         end
 
-        let(:plucked) do
-          Dictionary.all.pluck_each(:description).first
+        before do
+          I18n.with_locale { Dictionary.create!(description: 'english-text') }
         end
 
         it 'correctly uses the fallback' do
-          I18n.locale = :en
-          Dictionary.create!(description: 'english-text')
-          I18n.locale = :he
           expect(plucked).to eq 'english-text'
         end
       end
 
       context 'when the localized field is embedded' do
-        before do
-          p = Passport.new
-          I18n.locale = :en
-          p.name = 'Neil'
-          I18n.locale = :he
-          p.name = 'Nissim'
-
-          Person.create!(passport: p, employer_id: 12345)
-        end
+        let(:passport) { Passport.new }
 
         let(:plucked) do
           Person.where(employer_id: 12345).pluck_each('pass.name').first
@@ -2396,6 +2398,15 @@
           Person.where(employer_id: 12345).pluck_each('pass.name_translations.en').first
         end
 
+        around { |example| I18n.with_locale(:he) { example.run } }
+
+        before do
+          I18n.with_locale(:en) { passport.name = 'Neil' }
+          passport.name = 'Nissim'
+
+          Person.create!(passport: passport, employer_id: 12345)
+        end
+
         it 'returns the translation for the current locale' do
           expect(plucked).to eq('Nissim')
         end
diff --git a/spec/mongoid/fields/localized_spec.rb b/spec/mongoid/fields/localized_spec.rb
index 04c70c92a..4ab4331bd 100644
--- a/spec/mongoid/fields/localized_spec.rb
+++ b/spec/mongoid/fields/localized_spec.rb
@@ -83,9 +83,7 @@
       context 'when a locale is provided' do
         with_default_i18n_configs
 
-        before do
-          I18n.locale = :de
-        end
+        around { |example| I18n.with_locale(:de) { example.run } }
 
         context 'when the value exists' do
 
@@ -268,9 +266,7 @@
       context 'when a locale is provided' do
         with_default_i18n_configs
 
-        before do
-          I18n.locale = :de
-        end
+        around { |example| I18n.with_locale(:de) { example.run } }
 
         context 'when the value exists' do
 
@@ -302,6 +298,8 @@
             context 'when fallbacks are defined' do
               with_default_i18n_configs
 
+              around { |example| I18n.with_locale(:de) { example.run } }
+
               before do
                 I18n.fallbacks[:de] = %i[de en es]
               end
@@ -401,9 +399,7 @@
       context 'when a locale is provided' do
         with_default_i18n_configs
 
-        before do
-          I18n.locale = :de
-        end
+        around { |example| I18n.with_locale(:de) { example.run } }
 
         let(:value) do
           field.mongoize('This is a test')
@@ -435,9 +431,7 @@
       context 'when a locale is provided' do
         with_default_i18n_configs
 
-        before do
-          I18n.locale = :de
-        end
+        around { |example| I18n.with_locale(:de) { example.run } }
 
         let(:value) do
           field.mongoize('100')
@@ -451,9 +445,7 @@
       context 'when the type is Boolean' do
         with_default_i18n_configs
 
-        before do
-          I18n.locale = :de
-        end
+        around { |example| I18n.with_locale(:de) { example.run } }
 
         context 'when the value is false' do
 
@@ -489,14 +481,15 @@
           with_i18n_fallbacks
 
           context 'when the lookup does not need to use fallbacks' do
+            with_default_i18n_configs
 
-            context 'when the value is false' do
-              with_default_i18n_configs
+            around { |example| I18n.with_locale(:de) { example.run } }
 
-              before do
-                I18n.fallbacks[:de] = %i[en es]
-              end
+            before do
+              I18n.fallbacks[:de] = %i[en es]
+            end
 
+            context 'when the value is false' do
               let(:field) do
                 described_class.new(:boolean_value, localize: true, type: Mongoid::Boolean)
               end
@@ -513,6 +506,8 @@
             context 'when the value is true' do
               with_default_i18n_configs
 
+              around { |example| I18n.with_locale(:de) { example.run } }
+
               before do
                 I18n.fallbacks[:de] = %i[en es]
               end
diff --git a/spec/mongoid/fields_spec.rb b/spec/mongoid/fields_spec.rb
index 5c0158ac6..778b993b7 100644
--- a/spec/mongoid/fields_spec.rb
+++ b/spec/mongoid/fields_spec.rb
@@ -15,10 +15,12 @@
       context 'when translations exist' do
         with_default_i18n_configs
 
+        around { |example| I18n.with_locale(:de) { example.run } }
+
         before do
-          I18n.locale = :en
-          product.description = 'test'
-          I18n.locale = :de
+          I18n.with_locale(:en) do
+            product.description = 'test'
+          end
           product.description = 'The best'
         end
 
@@ -525,8 +527,9 @@
       context 'when a single locale is set' do
         with_default_i18n_configs
 
+        around { |example| I18n.with_locale(:de) { example.run } }
+
         before do
-          I18n.locale = :de
           product.description = 'The best'
         end
 
@@ -542,10 +545,10 @@
       context 'when multiple locales are set' do
         with_default_i18n_configs
 
+        around { |example| I18n.with_locale(:de) { example.run } }
+
         before do
-          I18n.locale = :end
-          product.description = 'Cheap drinks'
-          I18n.locale = :de
+          I18n.with_locale(:en) { product.description = 'Cheap drinks' }
           product.description = 'Cheaper drinks'
         end
 
@@ -871,8 +874,9 @@
       context 'when a locale is set' do
         with_default_i18n_configs
 
+        around { |example| I18n.with_locale(:de) { example.run } }
+
         before do
-          I18n.locale = :de
           product.description = 'Cheaper drinks'
         end
 
@@ -888,10 +892,10 @@
       context 'when having multiple locales' do
         with_default_i18n_configs
 
+        around { |example| I18n.with_locale(:de) { example.run } }
+
         before do
-          I18n.locale = :en
-          product.description = 'Cheap drinks'
-          I18n.locale = :de
+          I18n.with_locale(:en) { product.description = 'Cheap drinks' }
           product.description = 'Cheaper drinks'
         end
 
@@ -2052,10 +2056,10 @@ class DiscriminatorChild2 < DiscriminatorParent
     context 'when assigning an empty string' do
       with_default_i18n_configs
 
+      around { |example| I18n.with_locale(:de) { example.run } }
+
       before do
-        I18n.locale = :en
-        product.title = 'hello'
-        I18n.locale = :de
+        I18n.with_locale(:en) { product.title = 'hello' }
         product.title = 'hello there!'
         product.title = ''
       end
@@ -2072,10 +2076,10 @@ class DiscriminatorChild2 < DiscriminatorParent
     context 'when assigning nil' do
       with_default_i18n_configs
 
+      around { |example| I18n.with_locale(:de) { example.run } }
+
       before do
-        I18n.locale = :en
-        product.title = 'hello'
-        I18n.locale = :de
+        I18n.with_locale(:en) { product.title = 'hello' }
         product.title = 'hello there!'
         product.title = nil
       end
@@ -2092,10 +2096,10 @@ class DiscriminatorChild2 < DiscriminatorParent
     context 'when assigning an empty array' do
       with_default_i18n_configs
 
+      around { |example| I18n.with_locale(:de) { example.run } }
+
       before do
-        I18n.locale = :en
-        product.title = 'hello'
-        I18n.locale = :de
+        I18n.with_locale(:en) { product.title = 'hello' }
         product.title = 'hello there!'
         product.title = []
       end
diff --git a/spec/mongoid/persistable/updatable_spec.rb b/spec/mongoid/persistable/updatable_spec.rb
index ec3124f05..a985fb027 100644
--- a/spec/mongoid/persistable/updatable_spec.rb
+++ b/spec/mongoid/persistable/updatable_spec.rb
@@ -236,15 +236,20 @@
     context 'when persisting a localized field' do
       with_default_i18n_configs
 
-      let!(:product) do
-        Product.create!(description: 'The bomb')
-      end
+      let!(:product) { Product.new }
+
       let(:attributes) do
         product.attributes['description']
       end
 
+      around { |example| I18n.with_locale(:de) { example.run } }
+
       before do
-        I18n.locale = :de
+        I18n.with_locale(:en) do
+          product.description = 'The bomb'
+          product.save!
+        end
+
         product.update_attribute(:description, 'Die Bombe')
       end
 
diff --git a/spec/mongoid/validatable/uniqueness_spec.rb b/spec/mongoid/validatable/uniqueness_spec.rb
index 5b7d9582a..ba1112e2c 100644
--- a/spec/mongoid/validatable/uniqueness_spec.rb
+++ b/spec/mongoid/validatable/uniqueness_spec.rb
@@ -2521,8 +2521,9 @@ class SpanishActor < EuropeanActor
     context 'when using a different locale' do
       with_default_i18n_configs
 
+      around { |example| I18n.with_locale(:fr) { example.run } }
+
       before do
-        I18n.locale = :fr
         # Translation key location is as per rails-i18n gem.
         # See: https://github.com/svenfuchs/rails-i18n/blob/master/rails/locale/en.yml
         I18n.backend.store_translations(:fr, { errors: { messages: { taken: 'est déjà utilisé(e)' } } })
diff --git a/spec/support/macros.rb b/spec/support/macros.rb
index a99b331ef..420c586e9 100644
--- a/spec/support/macros.rb
+++ b/spec/support/macros.rb
@@ -110,13 +110,12 @@ def time_zone_override(time_zone)
 
     def with_default_i18n_configs
       around do |example|
-        I18n.locale = :en
         I18n.default_locale = :en
         I18n.try(:fallbacks=, I18n::Locale::Fallbacks.new)
         I18n.enforce_available_locales = false
-        example.run
+        I18n.with_locale(:en) { example.run }
       ensure
-        I18n.locale = :en
+        # I18n.locale = :en
         I18n.default_locale = :en
         I18n.try(:fallbacks=, I18n::Locale::Fallbacks.new)
         I18n.enforce_available_locales = false