diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index b49343f..65c528b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -14,19 +14,13 @@ jobs:
       matrix:
         include:
           # https://github.com/ruby/setup-ruby
-          - ruby: "head"
-            activerecord: "7.1"
+          # - ruby: "head" # cannot test on head as sqlite-ruby requires `ruby < '3.4.dev'`
+          #   activerecord: "8.0"
+          - ruby: "3.3"
+            activerecord: "8.0"
+          - ruby: "3.3"
+            activerecord: "7.2"
           - ruby: "3.3"
-            activerecord: "7.1"
-          - ruby: "3.2"
-            activerecord: "7.1"
-          - ruby: "3.1"
-            activerecord: "7.1"
-          - ruby: "3.0"
-            activerecord: "7.1"
-          - ruby: "2.7"
-            activerecord: "7.1"
-          - ruby: "2.7"
             activerecord: "6.1"
           - ruby: "2.7"
             activerecord: "5.2"
@@ -34,13 +28,15 @@ jobs:
             activerecord: "6.1"
           - ruby: "2.6"
             activerecord: "5.2"
-          - ruby: "jruby-9.4.5"
+          - ruby: "jruby-9.4.9"
             activerecord: "6.1"
-          - ruby: "jruby-9.4.5"
-            activerecord: "7.0" # latest activerecord-jdbcsqlite3-adapter (70.1) does not support latest rails 7.1 yet
-          - ruby: "truffleruby-23.1.1"
-            activerecord: "7.1"
-          - ruby: "truffleruby-23.1.1"
+          - ruby: "jruby-9.4.9"
+            activerecord: "7.2"
+          - ruby: "truffleruby-24.1.1"
+            activerecord: "8.0"
+          - ruby: "truffleruby-24.1.1"
+            activerecord: "7.2"
+          - ruby: "truffleruby-24.1.1"
             activerecord: "6.1"
 
     env:
@@ -49,7 +45,7 @@ jobs:
 
     steps:
       # https://github.com/actions/checkout
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       # https://github.com/ruby/setup-ruby
       - name: Set up Ruby ${{ matrix.ruby }} (AR ${{ matrix.activerecord }})
@@ -59,27 +55,27 @@ jobs:
           bundler-cache: true
 
       - name: Install codespell
-        if: startsWith(matrix.ruby, '3.2') && matrix.activerecord == '7.1'
+        if: startsWith(matrix.ruby, '3.3') && matrix.activerecord == '8.0'
         run: |
           python -m pip install --upgrade pip
-          pip install codespell==2.2.6
+          pip install codespell==2.3.0
       - name: Check spelling with codespell
-        if: startsWith(matrix.ruby, '3.2') && matrix.activerecord == '7.1'
+        if: startsWith(matrix.ruby, '3.3') && matrix.activerecord == '8.0'
         run: codespell --skip="./sig,./doc,./coverage,./vendor" || exit 1
 
       # Check code standards only for latest MRI. It takes a lot of time for jruby or truffleruby
       - name: Check Code Standards
-        if: startsWith(matrix.ruby, '3.2') && matrix.activerecord == '7.1'
+        if: startsWith(matrix.ruby, '3.3') && matrix.activerecord == '8.0'
         run: bundle exec rubocop
 
       - name: Run Tests
         run: bundle exec rspec
 
       - name: Markdown linter
-        if: startsWith(matrix.ruby, '3.2') && matrix.activerecord == '7.1'
+        if: startsWith(matrix.ruby, '3.3') && matrix.activerecord == '8.0'
         run: bundle exec mdl README.md CHANGELOG.md RELEASE.md
 
       # https://github.com/paambaati/codeclimate-action
       - name: Publish code coverage to code-climate
-        uses: paambaati/codeclimate-action@v3.2
-        if: (github.event_name == 'push') && startsWith(matrix.ruby, '3.2')
+        uses: paambaati/codeclimate-action@v9.0.0
+        if: (github.event_name == 'push') && startsWith(matrix.ruby, '3.3')
diff --git a/.rubocop.yml b/.rubocop.yml
index 9927685..d5f9a4d 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -26,9 +26,6 @@ Style/FrozenStringLiteralComment:
 RSpec/ExampleLength:
   Enabled: false
 
-RSpec/FilePath:
-  Enabled: false
-
 RSpec/IndexedLet:
   Enabled: false
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 769f305..f0b3328 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,15 +1,17 @@
 # CHANGELOG
 
-## [Unreleased]
+## [0.21.0] - 2024-11-19
 
 - Allow to provide modifiers and serialization options as strings. Only symbols
   were allowed previously.
 
+- Test compatibility with ActiveRecord 8.0.
+
 ## [0.20.1] - 2024-02-25
 
 - Fix issue with :if plugin used together with :batch plugin.
   We kept `key => nil` attribute when key should have been skipped
-  because of :if_value or :unelss_value option
+  because of :if_value or :unless_value option
 
 ## [0.20.0] - 2023-12-29
 
diff --git a/Gemfile b/Gemfile
index 30c4ee3..cc49cc0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,13 +7,12 @@ gemspec
 
 gem "rake", "~> 13.0"
 gem "rspec", "~> 3.0", require: false
-gem "standard", "~> 1.3", require: false
+gem "standard", "~> 1.42", require: false
 gem "simplecov", "~> 0.21", require: false
 gem "rubocop-rake", "~> 0.6.0", require: false
-gem "rubocop-rspec", "~> 2.11", ">= 2.11.1", require: false
-gem "rubocop-performance", "~> 1.20", require: false
+gem "rubocop-rspec", "~> 3.2.0", require: false
+gem "rubocop-performance", "~> 1.22", require: false
 gem "redcarpet", "~> 3.5", require: false
-gem "rspec-sqlimit", "~> 0.0.5", require: false
 # Can be used in test like:
 #  require 'allocation_stats'
 #
@@ -33,17 +32,6 @@ else
   gem "pry-byebug", "~> 3.9"
 end
 
-# ORM plugins
-ruby_version = Gem::Version.new(RUBY_VERSION)
-ar_version =
-  if ruby_version >= Gem::Version.new("3.0")
-    "~> 7.1"
-  elsif ruby_version >= Gem::Version.new("2.5")
-    "~> 6.1"
-  else
-    "~> 5.2"
-  end
-
-gem "activerecord", ar_version
+gem "activerecord", "~> 8.0"
 gem "sqlite3", platforms: [:ruby]
 gem "activerecord-jdbcsqlite3-adapter", platforms: [:jruby]
diff --git a/Gemfile.lock b/Gemfile.lock
index 553242b..4600d15 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,160 +1,154 @@
 PATH
   remote: .
   specs:
-    serega (0.20.1)
+    serega (0.21.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    activemodel (7.1.3.2)
-      activesupport (= 7.1.3.2)
-    activerecord (7.1.3.2)
-      activemodel (= 7.1.3.2)
-      activesupport (= 7.1.3.2)
+    activemodel (8.0.0)
+      activesupport (= 8.0.0)
+    activerecord (8.0.0)
+      activemodel (= 8.0.0)
+      activesupport (= 8.0.0)
       timeout (>= 0.4.0)
-    activesupport (7.1.3.2)
+    activesupport (8.0.0)
       base64
+      benchmark (>= 0.3)
       bigdecimal
-      concurrent-ruby (~> 1.0, >= 1.0.2)
+      concurrent-ruby (~> 1.0, >= 1.3.1)
       connection_pool (>= 2.2.5)
       drb
       i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
       minitest (>= 5.1)
-      mutex_m
-      tzinfo (~> 2.0)
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0, >= 2.0.5)
+      uri (>= 0.13.1)
     allocation_stats (0.1.5)
     ast (2.4.2)
     base64 (0.2.0)
-    bigdecimal (3.1.6)
-    chef-utils (18.4.2)
+    benchmark (0.4.0)
+    bigdecimal (3.1.8)
+    chef-utils (18.5.0)
       concurrent-ruby
-    concurrent-ruby (1.2.3)
+    concurrent-ruby (1.3.4)
     connection_pool (2.4.1)
-    debug (1.9.1)
+    debug (1.9.2)
       irb (~> 1.10)
       reline (>= 0.3.8)
     diff-lcs (1.5.1)
-    docile (1.4.0)
-    drb (2.2.0)
-      ruby2_keywords
-    i18n (1.14.1)
+    docile (1.4.1)
+    drb (2.2.1)
+    i18n (1.14.6)
       concurrent-ruby (~> 1.0)
     io-console (0.7.2)
-    irb (1.11.2)
-      rdoc
+    irb (1.14.1)
+      rdoc (>= 4.0.0)
       reline (>= 0.4.2)
-    json (2.7.1)
-    kramdown (2.4.0)
-      rexml
+    json (2.8.2)
+    kramdown (2.5.1)
+      rexml (>= 3.3.9)
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     language_server-protocol (3.17.0.3)
     lint_roller (1.1.0)
+    logger (1.6.1)
     mdl (0.13.0)
       kramdown (~> 2.3)
       kramdown-parser-gfm (~> 1.1)
       mixlib-cli (~> 2.1, >= 2.1.1)
       mixlib-config (>= 2.2.1, < 4)
       mixlib-shellout
-    minitest (5.22.2)
+    minitest (5.25.1)
     mixlib-cli (2.1.8)
     mixlib-config (3.0.27)
       tomlrb
-    mixlib-shellout (3.2.7)
+    mixlib-shellout (3.3.4)
       chef-utils
-    mutex_m (0.2.0)
-    parallel (1.24.0)
-    parser (3.3.0.5)
+    parallel (1.26.3)
+    parser (3.3.6.0)
       ast (~> 2.4.1)
       racc
-    psych (5.1.2)
+    psych (5.2.0)
       stringio
-    racc (1.7.3)
+    racc (1.8.1)
     rainbow (3.1.1)
-    rake (13.1.0)
-    rdoc (6.6.2)
+    rake (13.2.1)
+    rdoc (6.7.0)
       psych (>= 4.0.0)
     redcarpet (3.6.0)
-    regexp_parser (2.9.0)
-    reline (0.4.3)
+    regexp_parser (2.9.2)
+    reline (0.5.11)
       io-console (~> 0.5)
-    rexml (3.2.6)
+    rexml (3.3.9)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
       rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.0)
+    rspec-core (3.13.2)
       rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.0)
+    rspec-expectations (3.13.3)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.0)
+    rspec-mocks (3.13.2)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-sqlimit (0.0.6)
-      activerecord (>= 4.2.0, < 8)
-      rspec (~> 3.0)
     rspec-support (3.13.1)
-    rubocop (1.60.2)
+    rubocop (1.68.0)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
       parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.30.0, < 2.0)
+      regexp_parser (>= 2.4, < 3.0)
+      rubocop-ast (>= 1.32.2, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.30.0)
-      parser (>= 3.2.1.0)
-    rubocop-capybara (2.20.0)
-      rubocop (~> 1.41)
-    rubocop-factory_bot (2.25.1)
-      rubocop (~> 1.41)
-    rubocop-performance (1.20.2)
+    rubocop-ast (1.36.1)
+      parser (>= 3.3.1.0)
+    rubocop-performance (1.22.1)
       rubocop (>= 1.48.1, < 2.0)
-      rubocop-ast (>= 1.30.0, < 2.0)
+      rubocop-ast (>= 1.31.1, < 2.0)
     rubocop-rake (0.6.0)
       rubocop (~> 1.0)
-    rubocop-rspec (2.26.1)
-      rubocop (~> 1.40)
-      rubocop-capybara (~> 2.17)
-      rubocop-factory_bot (~> 2.22)
+    rubocop-rspec (3.2.0)
+      rubocop (~> 1.61)
     ruby-progressbar (1.13.0)
-    ruby2_keywords (0.0.5)
+    securerandom (0.3.2)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
+    simplecov-html (0.13.1)
     simplecov_json_formatter (0.1.4)
-    sqlite3 (1.7.2-x86_64-linux)
-    standard (1.34.0)
+    sqlite3 (2.2.0-x86_64-linux-gnu)
+    standard (1.42.0)
       language_server-protocol (~> 3.17.0.2)
       lint_roller (~> 1.0)
-      rubocop (~> 1.60)
+      rubocop (~> 1.68.0)
       standard-custom (~> 1.0.0)
-      standard-performance (~> 1.3)
+      standard-performance (~> 1.5)
     standard-custom (1.0.2)
       lint_roller (~> 1.0)
       rubocop (~> 1.50)
-    standard-performance (1.3.1)
+    standard-performance (1.5.0)
       lint_roller (~> 1.1)
-      rubocop-performance (~> 1.20.2)
-    stringio (3.1.0)
-    timeout (0.4.1)
+      rubocop-performance (~> 1.22.0)
+    stringio (3.1.2)
+    timeout (0.4.2)
     tomlrb (2.0.3)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (2.5.0)
-    yard (0.9.34)
+    unicode-display_width (2.6.0)
+    uri (1.0.2)
+    yard (0.9.37)
 
 PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
-  activerecord (~> 7.1)
+  activerecord (~> 8.0)
   activerecord-jdbcsqlite3-adapter
   allocation_stats
   debug (>= 1.0.0)
@@ -162,15 +156,14 @@ DEPENDENCIES
   rake (~> 13.0)
   redcarpet (~> 3.5)
   rspec (~> 3.0)
-  rspec-sqlimit (~> 0.0.5)
-  rubocop-performance (~> 1.20)
+  rubocop-performance (~> 1.22)
   rubocop-rake (~> 0.6.0)
-  rubocop-rspec (~> 2.11, >= 2.11.1)
+  rubocop-rspec (~> 3.2.0)
   serega!
   simplecov (~> 0.21)
   sqlite3
-  standard (~> 1.3)
+  standard (~> 1.42)
   yard
 
 BUNDLED WITH
-   2.5.6
+   2.5.23
diff --git a/RELEASE.md b/RELEASE.md
index c088901..223d82d 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -14,8 +14,8 @@
       && bundle update && bundle update --bundler \
       && BUNDLE_GEMFILE=gemfiles/5.2.gemfile bundle update \
       && BUNDLE_GEMFILE=gemfiles/6.1.gemfile bundle update \
-      && BUNDLE_GEMFILE=gemfiles/7.0.gemfile bundle update \
-      && BUNDLE_GEMFILE=gemfiles/7.1.gemfile bundle update \
+      && BUNDLE_GEMFILE=gemfiles/7.2.gemfile bundle update \
+      && BUNDLE_GEMFILE=gemfiles/8.0.gemfile bundle update \
       && bundle exec rspec \
       && bundle exec rubocop -A \
       && bundle exec rake examples \
@@ -44,6 +44,7 @@
       && BUNDLE_GEMFILE=gemfiles/6.1.gemfile bundle update \
       && BUNDLE_GEMFILE=gemfiles/7.0.gemfile bundle update \
       && BUNDLE_GEMFILE=gemfiles/7.1.gemfile bundle update \
+      && BUNDLE_GEMFILE=gemfiles/8.0.gemfile bundle update \
       && bundle exec rspec \
       && bundle exec rubocop -A \
       && bundle exec rake examples \
diff --git a/VERSION b/VERSION
index 847e9ae..8854156 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.20.1
+0.21.0
diff --git a/gemfiles/5.2.gemfile b/gemfiles/5.2.gemfile
index 30b6c8f..d16f671 100644
--- a/gemfiles/5.2.gemfile
+++ b/gemfiles/5.2.gemfile
@@ -8,6 +8,5 @@ gem "activerecord", "~> 5.2.3"
 
 gem "rake", "~> 13.0"
 gem "rspec", "~> 3.11", require: false
-gem "rspec-sqlimit", "~> 0.0.5", require: false
 
 gemspec name: "serega", path: "../"
diff --git a/gemfiles/5.2.gemfile.lock b/gemfiles/5.2.gemfile.lock
index bcd8e3b..2179a2f 100644
--- a/gemfiles/5.2.gemfile.lock
+++ b/gemfiles/5.2.gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    serega (0.20.1)
+    serega (0.21.0)
 
 GEM
   remote: https://rubygems.org/
@@ -23,29 +23,26 @@ GEM
       minitest (~> 5.1)
       tzinfo (~> 1.1)
     arel (9.0.0)
-    concurrent-ruby (1.2.3)
+    concurrent-ruby (1.3.4)
     diff-lcs (1.5.1)
-    i18n (1.14.1)
+    i18n (1.14.6)
       concurrent-ruby (~> 1.0)
     jdbc-sqlite3 (3.28.0)
-    mini_portile2 (2.8.5)
-    minitest (5.22.2)
-    rake (13.1.0)
+    mini_portile2 (2.8.8)
+    minitest (5.25.1)
+    rake (13.2.1)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
       rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.0)
+    rspec-core (3.13.2)
       rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.0)
+    rspec-expectations (3.13.3)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.0)
+    rspec-mocks (3.13.2)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-sqlimit (0.0.6)
-      activerecord (>= 4.2.0, < 8)
-      rspec (~> 3.0)
     rspec-support (3.13.1)
     sqlite3 (1.5.4)
       mini_portile2 (~> 2.8.0)
@@ -63,9 +60,8 @@ DEPENDENCIES
   activerecord-jdbcsqlite3-adapter
   rake (~> 13.0)
   rspec (~> 3.11)
-  rspec-sqlimit (~> 0.0.5)
   serega!
   sqlite3 (~> 1.5.4)
 
 BUNDLED WITH
-   2.4.22
+   2.5.23
diff --git a/gemfiles/6.1.gemfile b/gemfiles/6.1.gemfile
index ad9b8b4..ec9a257 100644
--- a/gemfiles/6.1.gemfile
+++ b/gemfiles/6.1.gemfile
@@ -8,6 +8,5 @@ gem "activerecord-jdbcsqlite3-adapter", "61.0", platforms: [:jruby]
 
 gem "rake", "~> 13.0"
 gem "rspec", "~> 3.11", require: false
-gem "rspec-sqlimit", "~> 0.0.5", require: false
 
 gemspec name: "serega", path: "../"
diff --git a/gemfiles/6.1.gemfile.lock b/gemfiles/6.1.gemfile.lock
index 7b5e4fc..d2ceaff 100644
--- a/gemfiles/6.1.gemfile.lock
+++ b/gemfiles/6.1.gemfile.lock
@@ -1,54 +1,51 @@
 PATH
   remote: ..
   specs:
-    serega (0.20.1)
+    serega (0.21.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    activemodel (6.1.7.7)
-      activesupport (= 6.1.7.7)
-    activerecord (6.1.7.7)
-      activemodel (= 6.1.7.7)
-      activesupport (= 6.1.7.7)
+    activemodel (6.1.7.10)
+      activesupport (= 6.1.7.10)
+    activerecord (6.1.7.10)
+      activemodel (= 6.1.7.10)
+      activesupport (= 6.1.7.10)
     activerecord-jdbc-adapter (61.0-java)
       activerecord (~> 6.1.0)
     activerecord-jdbcsqlite3-adapter (61.0-java)
       activerecord-jdbc-adapter (= 61.0)
       jdbc-sqlite3 (~> 3.8, < 3.30)
-    activesupport (6.1.7.7)
+    activesupport (6.1.7.10)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
       tzinfo (~> 2.0)
       zeitwerk (~> 2.3)
-    concurrent-ruby (1.2.3)
+    concurrent-ruby (1.3.4)
     diff-lcs (1.5.1)
-    i18n (1.14.1)
+    i18n (1.14.6)
       concurrent-ruby (~> 1.0)
     jdbc-sqlite3 (3.28.0)
-    minitest (5.22.2)
-    rake (13.1.0)
+    minitest (5.25.1)
+    rake (13.2.1)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
       rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.0)
+    rspec-core (3.13.2)
       rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.0)
+    rspec-expectations (3.13.3)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.0)
+    rspec-mocks (3.13.2)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-sqlimit (0.0.6)
-      activerecord (>= 4.2.0, < 8)
-      rspec (~> 3.0)
     rspec-support (3.13.1)
     sqlite3 (1.4.4)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    zeitwerk (2.6.13)
+    zeitwerk (2.7.1)
 
 PLATFORMS
   universal-java-11
@@ -59,9 +56,8 @@ DEPENDENCIES
   activerecord-jdbcsqlite3-adapter (= 61.0)
   rake (~> 13.0)
   rspec (~> 3.11)
-  rspec-sqlimit (~> 0.0.5)
   serega!
   sqlite3 (~> 1.4.4)
 
 BUNDLED WITH
-   2.4.22
+   2.5.23
diff --git a/gemfiles/7.0.gemfile b/gemfiles/7.0.gemfile
deleted file mode 100644
index 71ad4bb..0000000
--- a/gemfiles/7.0.gemfile
+++ /dev/null
@@ -1,18 +0,0 @@
-# frozen_string_literal: true
-
-source "https://rubygems.org"
-
-gem "sqlite3", "~> 1.4.4", platforms: [:ruby]
-gem "activerecord", "7.0.8"
-gem "activerecord-jdbcsqlite3-adapter", "~> 70.1", platforms: [:jruby]
-
-gem "rake", "~> 13.0"
-gem "standard", "~> 1.12", ">= 1.12.1", require: false
-gem "rspec", "~> 3.11", require: false
-gem "simplecov", "~> 0.21.2", require: false
-gem "rubocop-rake", "~> 0.6.0", require: false
-gem "rubocop-rspec", "~> 2.11", ">= 2.11.1", require: false
-gem "rspec-sqlimit", "~> 0.0.5", require: false
-gem "mdl", "~> 0.12.0", require: false
-
-gemspec name: "serega", path: "../"
diff --git a/gemfiles/7.0.gemfile.lock b/gemfiles/7.0.gemfile.lock
deleted file mode 100644
index db18ab8..0000000
--- a/gemfiles/7.0.gemfile.lock
+++ /dev/null
@@ -1,149 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    serega (0.20.1)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activemodel (7.0.8)
-      activesupport (= 7.0.8)
-    activerecord (7.0.8)
-      activemodel (= 7.0.8)
-      activesupport (= 7.0.8)
-    activerecord-jdbc-adapter (70.1-java)
-      activerecord (~> 7.0)
-    activerecord-jdbcsqlite3-adapter (70.1-java)
-      activerecord-jdbc-adapter (= 70.1)
-      jdbc-sqlite3 (~> 3.8, < 3.34)
-    activesupport (7.0.8)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      tzinfo (~> 2.0)
-    ast (2.4.2)
-    chef-utils (18.4.2)
-      concurrent-ruby
-    concurrent-ruby (1.2.3)
-    diff-lcs (1.5.1)
-    docile (1.4.0)
-    i18n (1.14.1)
-      concurrent-ruby (~> 1.0)
-    jdbc-sqlite3 (3.32.3.3)
-    json (2.7.1)
-    json (2.7.1-java)
-    kramdown (2.4.0)
-      rexml
-    kramdown-parser-gfm (1.1.0)
-      kramdown (~> 2.0)
-    language_server-protocol (3.17.0.3)
-    lint_roller (1.1.0)
-    mdl (0.12.0)
-      kramdown (~> 2.3)
-      kramdown-parser-gfm (~> 1.1)
-      mixlib-cli (~> 2.1, >= 2.1.1)
-      mixlib-config (>= 2.2.1, < 4)
-      mixlib-shellout
-    minitest (5.22.2)
-    mixlib-cli (2.1.8)
-    mixlib-config (3.0.27)
-      tomlrb
-    mixlib-shellout (3.2.7)
-      chef-utils
-    parallel (1.24.0)
-    parser (3.3.0.5)
-      ast (~> 2.4.1)
-      racc
-    racc (1.7.3)
-    racc (1.7.3-java)
-    rainbow (3.1.1)
-    rake (13.1.0)
-    regexp_parser (2.9.0)
-    rexml (3.2.6)
-    rspec (3.13.0)
-      rspec-core (~> 3.13.0)
-      rspec-expectations (~> 3.13.0)
-      rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.0)
-      rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.0)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.0)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-sqlimit (0.0.6)
-      activerecord (>= 4.2.0, < 8)
-      rspec (~> 3.0)
-    rspec-support (3.13.1)
-    rubocop (1.60.2)
-      json (~> 2.3)
-      language_server-protocol (>= 3.17.0)
-      parallel (~> 1.10)
-      parser (>= 3.3.0.2)
-      rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.30.0, < 2.0)
-      ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.30.0)
-      parser (>= 3.2.1.0)
-    rubocop-capybara (2.20.0)
-      rubocop (~> 1.41)
-    rubocop-factory_bot (2.25.1)
-      rubocop (~> 1.41)
-    rubocop-performance (1.20.2)
-      rubocop (>= 1.48.1, < 2.0)
-      rubocop-ast (>= 1.30.0, < 2.0)
-    rubocop-rake (0.6.0)
-      rubocop (~> 1.0)
-    rubocop-rspec (2.26.1)
-      rubocop (~> 1.40)
-      rubocop-capybara (~> 2.17)
-      rubocop-factory_bot (~> 2.22)
-    ruby-progressbar (1.13.0)
-    simplecov (0.21.2)
-      docile (~> 1.1)
-      simplecov-html (~> 0.11)
-      simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
-    simplecov_json_formatter (0.1.4)
-    sqlite3 (1.4.4)
-    standard (1.34.0)
-      language_server-protocol (~> 3.17.0.2)
-      lint_roller (~> 1.0)
-      rubocop (~> 1.60)
-      standard-custom (~> 1.0.0)
-      standard-performance (~> 1.3)
-    standard-custom (1.0.2)
-      lint_roller (~> 1.0)
-      rubocop (~> 1.50)
-    standard-performance (1.3.1)
-      lint_roller (~> 1.1)
-      rubocop-performance (~> 1.20.2)
-    tomlrb (2.0.3)
-    tzinfo (2.0.6)
-      concurrent-ruby (~> 1.0)
-    unicode-display_width (2.5.0)
-
-PLATFORMS
-  universal-java-11
-  x86_64-linux
-
-DEPENDENCIES
-  activerecord (= 7.0.8)
-  activerecord-jdbcsqlite3-adapter (~> 70.1)
-  mdl (~> 0.12.0)
-  rake (~> 13.0)
-  rspec (~> 3.11)
-  rspec-sqlimit (~> 0.0.5)
-  rubocop-rake (~> 0.6.0)
-  rubocop-rspec (~> 2.11, >= 2.11.1)
-  serega!
-  simplecov (~> 0.21.2)
-  sqlite3 (~> 1.4.4)
-  standard (~> 1.12, >= 1.12.1)
-
-BUNDLED WITH
-   2.4.22
diff --git a/gemfiles/7.1.gemfile.lock b/gemfiles/7.1.gemfile.lock
deleted file mode 100644
index bdea62f..0000000
--- a/gemfiles/7.1.gemfile.lock
+++ /dev/null
@@ -1,164 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    serega (0.20.1)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activemodel (7.1.3.2)
-      activesupport (= 7.1.3.2)
-    activerecord (7.1.3.2)
-      activemodel (= 7.1.3.2)
-      activesupport (= 7.1.3.2)
-      timeout (>= 0.4.0)
-    activerecord-jdbc-adapter (70.1-java)
-      activerecord (~> 7.0)
-    activerecord-jdbcsqlite3-adapter (70.1-java)
-      activerecord-jdbc-adapter (= 70.1)
-      jdbc-sqlite3 (~> 3.8, < 3.34)
-    activesupport (7.1.3.2)
-      base64
-      bigdecimal
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      connection_pool (>= 2.2.5)
-      drb
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      mutex_m
-      tzinfo (~> 2.0)
-    ast (2.4.2)
-    base64 (0.2.0)
-    bigdecimal (3.1.6)
-    bigdecimal (3.1.6-java)
-    chef-utils (18.4.2)
-      concurrent-ruby
-    concurrent-ruby (1.2.3)
-    connection_pool (2.4.1)
-    diff-lcs (1.5.1)
-    docile (1.4.0)
-    drb (2.2.0)
-      ruby2_keywords
-    i18n (1.14.1)
-      concurrent-ruby (~> 1.0)
-    jdbc-sqlite3 (3.32.3.3)
-    json (2.7.1)
-    json (2.7.1-java)
-    kramdown (2.4.0)
-      rexml
-    kramdown-parser-gfm (1.1.0)
-      kramdown (~> 2.0)
-    language_server-protocol (3.17.0.3)
-    lint_roller (1.1.0)
-    mdl (0.12.0)
-      kramdown (~> 2.3)
-      kramdown-parser-gfm (~> 1.1)
-      mixlib-cli (~> 2.1, >= 2.1.1)
-      mixlib-config (>= 2.2.1, < 4)
-      mixlib-shellout
-    minitest (5.22.2)
-    mixlib-cli (2.1.8)
-    mixlib-config (3.0.27)
-      tomlrb
-    mixlib-shellout (3.2.7)
-      chef-utils
-    mutex_m (0.2.0)
-    parallel (1.24.0)
-    parser (3.3.0.5)
-      ast (~> 2.4.1)
-      racc
-    racc (1.7.3)
-    racc (1.7.3-java)
-    rainbow (3.1.1)
-    rake (13.1.0)
-    regexp_parser (2.9.0)
-    rexml (3.2.6)
-    rspec (3.13.0)
-      rspec-core (~> 3.13.0)
-      rspec-expectations (~> 3.13.0)
-      rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.0)
-      rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.0)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.0)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-sqlimit (0.0.6)
-      activerecord (>= 4.2.0, < 8)
-      rspec (~> 3.0)
-    rspec-support (3.13.1)
-    rubocop (1.60.2)
-      json (~> 2.3)
-      language_server-protocol (>= 3.17.0)
-      parallel (~> 1.10)
-      parser (>= 3.3.0.2)
-      rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.30.0, < 2.0)
-      ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.30.0)
-      parser (>= 3.2.1.0)
-    rubocop-capybara (2.20.0)
-      rubocop (~> 1.41)
-    rubocop-factory_bot (2.25.1)
-      rubocop (~> 1.41)
-    rubocop-performance (1.20.2)
-      rubocop (>= 1.48.1, < 2.0)
-      rubocop-ast (>= 1.30.0, < 2.0)
-    rubocop-rake (0.6.0)
-      rubocop (~> 1.0)
-    rubocop-rspec (2.26.1)
-      rubocop (~> 1.40)
-      rubocop-capybara (~> 2.17)
-      rubocop-factory_bot (~> 2.22)
-    ruby-progressbar (1.13.0)
-    ruby2_keywords (0.0.5)
-    simplecov (0.21.2)
-      docile (~> 1.1)
-      simplecov-html (~> 0.11)
-      simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
-    simplecov_json_formatter (0.1.4)
-    sqlite3 (1.4.4)
-    standard (1.34.0)
-      language_server-protocol (~> 3.17.0.2)
-      lint_roller (~> 1.0)
-      rubocop (~> 1.60)
-      standard-custom (~> 1.0.0)
-      standard-performance (~> 1.3)
-    standard-custom (1.0.2)
-      lint_roller (~> 1.0)
-      rubocop (~> 1.50)
-    standard-performance (1.3.1)
-      lint_roller (~> 1.1)
-      rubocop-performance (~> 1.20.2)
-    timeout (0.4.1)
-    tomlrb (2.0.3)
-    tzinfo (2.0.6)
-      concurrent-ruby (~> 1.0)
-    unicode-display_width (2.5.0)
-
-PLATFORMS
-  universal-java-11
-  x86_64-linux
-
-DEPENDENCIES
-  activerecord (~> 7.1, >= 7.1.1)
-  activerecord-jdbcsqlite3-adapter
-  mdl (~> 0.12.0)
-  rake (~> 13.0)
-  rspec (~> 3.11)
-  rspec-sqlimit (~> 0.0.5)
-  rubocop-rake (~> 0.6.0)
-  rubocop-rspec (~> 2.11, >= 2.11.1)
-  serega!
-  simplecov (~> 0.21.2)
-  sqlite3 (~> 1.4.4)
-  standard (~> 1.12, >= 1.12.1)
-
-BUNDLED WITH
-   2.4.22
diff --git a/gemfiles/7.2.gemfile b/gemfiles/7.2.gemfile
new file mode 100644
index 0000000..a0fbc50
--- /dev/null
+++ b/gemfiles/7.2.gemfile
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+gem "activerecord-jdbcsqlite3-adapter", platforms: [:jruby]
+gem "sqlite3", "~> 1.4.4", platforms: [:ruby]
+gem "activerecord", "~> 7.2"
+
+gem "rake", "~> 13.0"
+gem "rspec", "~> 3.11", require: false
+
+gemspec name: "serega", path: "../"
diff --git a/gemfiles/7.2.gemfile.lock b/gemfiles/7.2.gemfile.lock
new file mode 100644
index 0000000..01bba65
--- /dev/null
+++ b/gemfiles/7.2.gemfile.lock
@@ -0,0 +1,78 @@
+PATH
+  remote: ..
+  specs:
+    serega (0.21.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activemodel (7.2.2)
+      activesupport (= 7.2.2)
+    activerecord (7.2.2)
+      activemodel (= 7.2.2)
+      activesupport (= 7.2.2)
+      timeout (>= 0.4.0)
+    activerecord-jdbc-adapter (70.2-java)
+      activerecord (~> 7.0)
+    activerecord-jdbcsqlite3-adapter (70.2-java)
+      activerecord-jdbc-adapter (= 70.2)
+      jdbc-sqlite3 (~> 3.8)
+    activesupport (7.2.2)
+      base64
+      benchmark (>= 0.3)
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.3.1)
+      connection_pool (>= 2.2.5)
+      drb
+      i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
+      minitest (>= 5.1)
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0, >= 2.0.5)
+    base64 (0.2.0)
+    benchmark (0.4.0)
+    bigdecimal (3.1.8)
+    bigdecimal (3.1.8-java)
+    concurrent-ruby (1.3.4)
+    connection_pool (2.4.1)
+    diff-lcs (1.5.1)
+    drb (2.2.1)
+    i18n (1.14.6)
+      concurrent-ruby (~> 1.0)
+    jdbc-sqlite3 (3.46.1.1)
+    logger (1.6.1)
+    minitest (5.25.1)
+    rake (13.2.1)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.2)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.3)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.1)
+    securerandom (0.3.2)
+    sqlite3 (1.4.4)
+    timeout (0.4.2)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+
+PLATFORMS
+  universal-java-11
+  x86_64-linux
+
+DEPENDENCIES
+  activerecord (~> 7.2)
+  activerecord-jdbcsqlite3-adapter
+  rake (~> 13.0)
+  rspec (~> 3.11)
+  serega!
+  sqlite3 (~> 1.4.4)
+
+BUNDLED WITH
+   2.5.23
diff --git a/gemfiles/7.1.gemfile b/gemfiles/8.0.gemfile
similarity index 53%
rename from gemfiles/7.1.gemfile
rename to gemfiles/8.0.gemfile
index 1e85a61..3f62343 100644
--- a/gemfiles/7.1.gemfile
+++ b/gemfiles/8.0.gemfile
@@ -3,16 +3,15 @@
 source "https://rubygems.org"
 
 gem "activerecord-jdbcsqlite3-adapter", platforms: [:jruby]
-gem "sqlite3", "~> 1.4.4", platforms: [:ruby]
-gem "activerecord", "~> 7.1", ">= 7.1.1"
+gem "sqlite3", "~> 2.2.0", platforms: [:ruby]
+gem "activerecord", "~> 8.0"
 
 gem "rake", "~> 13.0"
 gem "standard", "~> 1.12", ">= 1.12.1", require: false
 gem "rspec", "~> 3.11", require: false
-gem "simplecov", "~> 0.21.2", require: false
+gem "simplecov", "~> 0.22", require: false
 gem "rubocop-rake", "~> 0.6.0", require: false
-gem "rubocop-rspec", "~> 2.11", ">= 2.11.1", require: false
-gem "rspec-sqlimit", "~> 0.0.5", require: false
-gem "mdl", "~> 0.12.0", require: false
+gem "rubocop-rspec", "~> 3.2.0", require: false
+gem "mdl", "~> 0.13.0", require: false
 
 gemspec name: "serega", path: "../"
diff --git a/gemfiles/8.0.gemfile.lock b/gemfiles/8.0.gemfile.lock
new file mode 100644
index 0000000..a03f674
--- /dev/null
+++ b/gemfiles/8.0.gemfile.lock
@@ -0,0 +1,151 @@
+PATH
+  remote: ..
+  specs:
+    serega (0.21.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activemodel (8.0.0)
+      activesupport (= 8.0.0)
+    activerecord (8.0.0)
+      activemodel (= 8.0.0)
+      activesupport (= 8.0.0)
+      timeout (>= 0.4.0)
+    activesupport (8.0.0)
+      base64
+      benchmark (>= 0.3)
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.3.1)
+      connection_pool (>= 2.2.5)
+      drb
+      i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
+      minitest (>= 5.1)
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0, >= 2.0.5)
+      uri (>= 0.13.1)
+    ast (2.4.2)
+    base64 (0.2.0)
+    benchmark (0.4.0)
+    bigdecimal (3.1.8)
+    chef-utils (18.5.0)
+      concurrent-ruby
+    concurrent-ruby (1.3.4)
+    connection_pool (2.4.1)
+    diff-lcs (1.5.1)
+    docile (1.4.1)
+    drb (2.2.1)
+    i18n (1.14.6)
+      concurrent-ruby (~> 1.0)
+    json (2.8.2)
+    kramdown (2.5.1)
+      rexml (>= 3.3.9)
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
+    language_server-protocol (3.17.0.3)
+    lint_roller (1.1.0)
+    logger (1.6.1)
+    mdl (0.13.0)
+      kramdown (~> 2.3)
+      kramdown-parser-gfm (~> 1.1)
+      mixlib-cli (~> 2.1, >= 2.1.1)
+      mixlib-config (>= 2.2.1, < 4)
+      mixlib-shellout
+    mini_portile2 (2.8.8)
+    minitest (5.25.1)
+    mixlib-cli (2.1.8)
+    mixlib-config (3.0.27)
+      tomlrb
+    mixlib-shellout (3.3.4)
+      chef-utils
+    parallel (1.26.3)
+    parser (3.3.6.0)
+      ast (~> 2.4.1)
+      racc
+    racc (1.8.1)
+    rainbow (3.1.1)
+    rake (13.2.1)
+    regexp_parser (2.9.2)
+    rexml (3.3.9)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.2)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.3)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.1)
+    rubocop (1.68.0)
+      json (~> 2.3)
+      language_server-protocol (>= 3.17.0)
+      parallel (~> 1.10)
+      parser (>= 3.3.0.2)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.4, < 3.0)
+      rubocop-ast (>= 1.32.2, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 3.0)
+    rubocop-ast (1.36.1)
+      parser (>= 3.3.1.0)
+    rubocop-performance (1.22.1)
+      rubocop (>= 1.48.1, < 2.0)
+      rubocop-ast (>= 1.31.1, < 2.0)
+    rubocop-rake (0.6.0)
+      rubocop (~> 1.0)
+    rubocop-rspec (3.2.0)
+      rubocop (~> 1.61)
+    ruby-progressbar (1.13.0)
+    securerandom (0.3.2)
+    simplecov (0.22.0)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.13.1)
+    simplecov_json_formatter (0.1.4)
+    sqlite3 (2.2.0)
+      mini_portile2 (~> 2.8.0)
+    sqlite3 (2.2.0-x86_64-linux-gnu)
+    standard (1.42.0)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.0)
+      rubocop (~> 1.68.0)
+      standard-custom (~> 1.0.0)
+      standard-performance (~> 1.5)
+    standard-custom (1.0.2)
+      lint_roller (~> 1.0)
+      rubocop (~> 1.50)
+    standard-performance (1.5.0)
+      lint_roller (~> 1.1)
+      rubocop-performance (~> 1.22.0)
+    timeout (0.4.2)
+    tomlrb (2.0.3)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+    unicode-display_width (2.6.0)
+    uri (1.0.2)
+
+PLATFORMS
+  ruby
+  x86_64-linux
+
+DEPENDENCIES
+  activerecord (~> 8.0)
+  activerecord-jdbcsqlite3-adapter
+  mdl (~> 0.13.0)
+  rake (~> 13.0)
+  rspec (~> 3.11)
+  rubocop-rake (~> 0.6.0)
+  rubocop-rspec (~> 3.2.0)
+  serega!
+  simplecov (~> 0.22)
+  sqlite3 (~> 2.2.0)
+  standard (~> 1.12, >= 1.12.1)
+
+BUNDLED WITH
+   2.5.23
diff --git a/spec/serega/plugins/batch/lib/plugin_extensions/activerecord_preloads_spec.rb b/spec/serega/plugins/batch/lib/plugin_extensions/activerecord_preloads_spec.rb
index b623165..3cae583 100644
--- a/spec/serega/plugins/batch/lib/plugin_extensions/activerecord_preloads_spec.rb
+++ b/spec/serega/plugins/batch/lib/plugin_extensions/activerecord_preloads_spec.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require "support/activerecord"
-require "rspec-sqlimit"
 
 load_plugin_code :batch
 
@@ -71,13 +70,17 @@ def groups(values, by:)
     it "preloads data to batch loaded records", :with_rollback do
       users = AR::User.all
 
-      result = nil
-      expect { result = user_serializer.to_h(users) }.not_to exceed_query_limit(3)
+      queries_count = 0
+      ActiveSupport::Notifications.subscribe("sql.active_record") { queries_count += 1 }
+
+      result = user_serializer.to_h(users)
 
       expect(result.count).to eq 1 # 1 user
       expect(result[0][:posts].count).to eq 2 # 2 posts
       expect(result[0][:posts][0][:comments].count).to eq 2 # 2 comments of post1
       expect(result[0][:posts][1][:comments].count).to eq 1 # 1 comment of post2
+
+      expect(queries_count).to eq 3
     end
   end
 
@@ -102,11 +105,15 @@ def groups(values, by:)
     it "preloads data correctly", :with_rollback do
       users = AR::User.all
 
-      result = nil
-      expect { result = user_serializer.to_h(users) }.not_to exceed_query_limit(3)
+      queries_count = 0
+      ActiveSupport::Notifications.subscribe("sql.active_record") { queries_count += 1 }
+
+      result = user_serializer.to_h(users)
 
       expect(result[0][:posts_count]).to eq 2
       expect(result[0][:comments_count]).to eq 3
+
+      expect(queries_count).to eq 3
     end
   end
 
@@ -146,14 +153,17 @@ def groups(values, by:)
 
     it "preloads data to batch loaded records", :with_rollback do
       users = AR::User.all
+      queries_count = 0
+      ActiveSupport::Notifications.subscribe("sql.active_record") { queries_count += 1 }
 
-      result = nil
-      expect { result = user_serializer.to_h(users) }.not_to exceed_query_limit(3)
+      result = user_serializer.to_h(users)
 
       expect(result.count).to eq 1 # 1 user
       expect(result[0][:posts].count).to eq 2 # 2 posts
       expect(result[0][:posts][0][:comments].count).to eq 2 # 2 comments of post1
       expect(result[0][:posts][1][:comments].count).to eq 1 # 1 comment of post2
+
+      expect(queries_count).to eq 3
     end
   end
 end
diff --git a/spec/serega/plugins/presenter/presenter_spec.rb b/spec/serega/plugins/presenter/presenter_spec.rb
index 95933ca..ce6d97f 100644
--- a/spec/serega/plugins/presenter/presenter_spec.rb
+++ b/spec/serega/plugins/presenter/presenter_spec.rb
@@ -53,8 +53,10 @@ def value
   end
 
   it "works in nested relation" do
+    struct = Struct.new(:nested).new("123")
+
     current_serializer = serializer
-    serializer.attribute(:rev) { |obj| obj.rev }
+    current_serializer.attribute(:rev)
     current_serializer::Presenter.class_exec do
       def rev
         reverse
@@ -65,9 +67,7 @@ def rev
       attribute :nested, serializer: current_serializer
     end
 
-    base = OpenStruct.new(nested: "123")
-
-    result = base_serializer.new.to_h(base)
+    result = base_serializer.new.to_h(struct, many: false)
     expect(result).to eq({nested: {rev: "321"}})
   end
 end
diff --git a/spec/support/activerecord.rb b/spec/support/activerecord.rb
index c6b30c8..e4107d3 100644
--- a/spec/support/activerecord.rb
+++ b/spec/support/activerecord.rb
@@ -2,7 +2,7 @@
 
 require "active_record"
 
-conn = ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:").connection
+conn = ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:").lease_connection
 
 conn.create_table(:users) do |t|
   t.string :first_name