diff --git a/.github/workflows/REUSABLE_backend.yml b/.github/workflows/REUSABLE_backend.yml
index 57923a412..67203d3e3 100644
--- a/.github/workflows/REUSABLE_backend.yml
+++ b/.github/workflows/REUSABLE_backend.yml
@@ -21,6 +21,12 @@ on:
         required: false
         default: '.'
 
+      # Only relevant in mono-repos.
+      monorepo_tests:
+        description: "The list of directories to test in a monorepo. This should be a space-separated list of directories relative to the backend directory."
+        type: string
+        required: false
+
       php_versions:
         description: Versions of PHP to test with. Should be array of strings encoded as JSON array
         type: string
@@ -47,6 +53,7 @@ on:
 
 env:
   COMPOSER_ROOT_VERSION: dev-main
+  # `inputs.composer_directory` defaults to `inputs.backend_directory`
   FLARUM_TEST_TMP_DIR_LOCAL: tests/integration/tmp
 
 jobs:
@@ -143,18 +150,27 @@ jobs:
         run: composer install
         working-directory: ${{ inputs.backend_directory }}
 
-      - name: Setup Composer tests
-        run: composer test:setup
+      # If we have a `inputs.monorepo_tests`, we will run tests for each item of the provided array in a ::group::item
+      # If we don't have a `inputs.monorepo_tests`, we will run tests for the current repository
+      # We also have to run the `composer test:setup` script first before running each test
+      - name: Run tests
+        run: |
+          if [ -z "${{ inputs.monorepo_tests }}" ]; then
+            composer test:setup
+            composer test
+          else
+            for test in ${{ inputs.monorepo_tests }}; do
+              echo "::group::Running tests for $test"
+              composer test:setup --working-dir=$test
+              composer test --working-dir=$test
+              echo "::endgroup::"
+            done
+          fi
         working-directory: ${{ inputs.backend_directory }}
         env:
           DB_PORT: 13306
           DB_PASSWORD: root
           DB_PREFIX: ${{ matrix.prefix }}
-
-      - name: Run Composer tests
-        run: composer test
-        working-directory: ${{ inputs.backend_directory }}
-        env:
           COMPOSER_PROCESS_TIMEOUT: 600
 
   phpstan:
diff --git a/.github/workflows/backend.yml b/.github/workflows/backend.yml
new file mode 100644
index 000000000..fad36a3ad
--- /dev/null
+++ b/.github/workflows/backend.yml
@@ -0,0 +1,11 @@
+name: Backend Tests
+
+on: [workflow_dispatch, push, pull_request]
+
+jobs:
+  run:
+    uses: ./.github/workflows/REUSABLE_backend.yml
+    with:
+      enable_backend_testing: true
+      backend_directory: .
+      monorepo_tests: "framework/core extensions/akismet extensions/approval extensions/flags extensions/likes extensions/mentions extensions/nicknames extensions/statistics extensions/sticky extensions/subscriptions extensions/suspend extensions/tags"
diff --git a/.github/workflows/flarum-akismet-backend.yml b/.github/workflows/flarum-akismet-backend.yml
deleted file mode 100644
index a493e93da..000000000
--- a/.github/workflows/flarum-akismet-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Akismet PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/akismet
diff --git a/.github/workflows/flarum-approval-backend.yml b/.github/workflows/flarum-approval-backend.yml
deleted file mode 100644
index fec282a69..000000000
--- a/.github/workflows/flarum-approval-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Approval PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/approval
diff --git a/.github/workflows/flarum-core-backend.yml b/.github/workflows/flarum-core-backend.yml
deleted file mode 100644
index 501757382..000000000
--- a/.github/workflows/flarum-core-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Core PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./framework/core
diff --git a/.github/workflows/flarum-embed-backend.yml b/.github/workflows/flarum-embed-backend.yml
deleted file mode 100644
index 41325d9d7..000000000
--- a/.github/workflows/flarum-embed-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Embed PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: false
-
-      backend_directory: ./extensions/embed
diff --git a/.github/workflows/flarum-emoji-backend.yml b/.github/workflows/flarum-emoji-backend.yml
deleted file mode 100644
index ff8a402e9..000000000
--- a/.github/workflows/flarum-emoji-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Emoji PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: false
-
-      backend_directory: ./extensions/emoji
diff --git a/.github/workflows/flarum-flags-backend.yml b/.github/workflows/flarum-flags-backend.yml
deleted file mode 100644
index ec8f91d87..000000000
--- a/.github/workflows/flarum-flags-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Flags PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/flags
diff --git a/.github/workflows/flarum-likes-backend.yml b/.github/workflows/flarum-likes-backend.yml
deleted file mode 100644
index a3347bd12..000000000
--- a/.github/workflows/flarum-likes-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Likes PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/likes
diff --git a/.github/workflows/flarum-lock-backend.yml b/.github/workflows/flarum-lock-backend.yml
deleted file mode 100644
index a8ddba992..000000000
--- a/.github/workflows/flarum-lock-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Lock PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: false
-
-      backend_directory: ./extensions/lock
diff --git a/.github/workflows/flarum-markdown-backend.yml b/.github/workflows/flarum-markdown-backend.yml
deleted file mode 100644
index f1022fd5c..000000000
--- a/.github/workflows/flarum-markdown-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Markdown PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: false
-
-      backend_directory: ./extensions/markdown
diff --git a/.github/workflows/flarum-mentions-backend.yml b/.github/workflows/flarum-mentions-backend.yml
deleted file mode 100644
index 4955837bf..000000000
--- a/.github/workflows/flarum-mentions-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Mentions PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/mentions
diff --git a/.github/workflows/flarum-nicknames-backend.yml b/.github/workflows/flarum-nicknames-backend.yml
deleted file mode 100644
index 602bba515..000000000
--- a/.github/workflows/flarum-nicknames-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Nicknames PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/nicknames
diff --git a/.github/workflows/flarum-package-manager-backend.yml b/.github/workflows/flarum-package-manager-backend.yml
deleted file mode 100644
index 77a12e945..000000000
--- a/.github/workflows/flarum-package-manager-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Package Manager PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: false
-
-      backend_directory: ./extensions/package-manager
diff --git a/.github/workflows/flarum-pusher-backend.yml b/.github/workflows/flarum-pusher-backend.yml
deleted file mode 100644
index cc9216274..000000000
--- a/.github/workflows/flarum-pusher-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Pusher PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: false
-
-      backend_directory: ./extensions/pusher
diff --git a/.github/workflows/flarum-statistics-backend.yml b/.github/workflows/flarum-statistics-backend.yml
deleted file mode 100644
index 514222f9f..000000000
--- a/.github/workflows/flarum-statistics-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Statistics PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/statistics
diff --git a/.github/workflows/flarum-sticky-backend.yml b/.github/workflows/flarum-sticky-backend.yml
deleted file mode 100644
index d86994abc..000000000
--- a/.github/workflows/flarum-sticky-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Sticky PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/sticky
diff --git a/.github/workflows/flarum-subscriptions-backend.yml b/.github/workflows/flarum-subscriptions-backend.yml
deleted file mode 100644
index cfd21a0c4..000000000
--- a/.github/workflows/flarum-subscriptions-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Subscriptions PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/subscriptions
diff --git a/.github/workflows/flarum-suspend-backend.yml b/.github/workflows/flarum-suspend-backend.yml
deleted file mode 100644
index b65d7fb07..000000000
--- a/.github/workflows/flarum-suspend-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Suspend PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/suspend
diff --git a/.github/workflows/flarum-tags-backend.yml b/.github/workflows/flarum-tags-backend.yml
deleted file mode 100644
index 622090822..000000000
--- a/.github/workflows/flarum-tags-backend.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-name: Tags PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-jobs:
-  run:
-    uses: ./.github/workflows/REUSABLE_backend.yml
-    with:
-      enable_backend_testing: true
-
-      backend_directory: ./extensions/tags
diff --git a/.github/workflows/frontend.yml b/.github/workflows/frontend.yml
index 0c9ff9563..c70458f8c 100755
--- a/.github/workflows/frontend.yml
+++ b/.github/workflows/frontend.yml
@@ -1,4 +1,4 @@
-name: Framework JS
+name: Frontend Workflow
 
 on: [workflow_dispatch, push, pull_request]
 
diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index e0088cfd2..edb7d27e6 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -1,4 +1,4 @@
-name: Framework PHP
+name: Static Code Analysis
 
 on: [workflow_dispatch, push, pull_request]
 
@@ -8,5 +8,4 @@ jobs:
     with:
       enable_backend_testing: false
       enable_phpstan: true
-
       backend_directory: .
diff --git a/composer.json b/composer.json
index 5e4b8d787..d6163bfb5 100644
--- a/composer.json
+++ b/composer.json
@@ -60,6 +60,26 @@
             "framework/core/src/helpers.php"
         ]
     },
+    "autoload-dev": {
+        "psr-4": {
+            "Flarum\\Tests\\": "tests",
+            "Flarum\\Akismet\\Tests\\": "extensions/akismet/tests",
+            "Flarum\\Approval\\Tests\\": "extensions/approval/tests",
+            "Flarum\\Flags\\Tests\\": "extensions/flags/tests",
+            "Flarum\\Likes\\Tests\\": "extensions/likes/tests",
+            "Flarum\\Lock\\Tests\\": "extensions/lock/tests",
+            "Flarum\\Mentions\\Tests\\": "extensions/mentions/tests",
+            "Flarum\\Nicknames\\Tests\\": "extensions/nicknames/tests",
+            "Flarum\\PackageManager\\Tests\\": "extensions/package-manager/tests",
+            "Flarum\\Pusher\\Tests\\": "extensions/pusher/tests",
+            "Flarum\\Statistics\\Tests\\": "extensions/statistics/tests",
+            "Flarum\\Sticky\\Tests\\": "extensions/sticky/tests",
+            "Flarum\\Subscriptions\\Tests\\": "extensions/subscriptions/tests",
+            "Flarum\\Suspend\\Tests\\": "extensions/suspend/tests",
+            "Flarum\\Tags\\Tests\\": "extensions/tags/tests",
+            "Flarum\\Testing\\Tests\\": "php-packages/testing/tests"
+        }
+    },
     "replace": {
         "flarum/core": "self.version",
         "flarum/akismet": "self.version",
diff --git a/extensions/akismet/tests/integration/setup.php b/extensions/akismet/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/akismet/tests/integration/setup.php
+++ b/extensions/akismet/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/akismet/tests/phpunit.integration.xml b/extensions/akismet/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/akismet/tests/phpunit.integration.xml
+++ b/extensions/akismet/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/akismet/tests/phpunit.unit.xml b/extensions/akismet/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/akismet/tests/phpunit.unit.xml
+++ b/extensions/akismet/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/approval/tests/integration/setup.php b/extensions/approval/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/approval/tests/integration/setup.php
+++ b/extensions/approval/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/approval/tests/phpunit.integration.xml b/extensions/approval/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/approval/tests/phpunit.integration.xml
+++ b/extensions/approval/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/approval/tests/phpunit.unit.xml b/extensions/approval/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/approval/tests/phpunit.unit.xml
+++ b/extensions/approval/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/flags/tests/integration/setup.php b/extensions/flags/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/flags/tests/integration/setup.php
+++ b/extensions/flags/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/flags/tests/phpunit.integration.xml b/extensions/flags/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/flags/tests/phpunit.integration.xml
+++ b/extensions/flags/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/flags/tests/phpunit.unit.xml b/extensions/flags/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/flags/tests/phpunit.unit.xml
+++ b/extensions/flags/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/likes/tests/integration/setup.php b/extensions/likes/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/likes/tests/integration/setup.php
+++ b/extensions/likes/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/likes/tests/phpunit.integration.xml b/extensions/likes/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/likes/tests/phpunit.integration.xml
+++ b/extensions/likes/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/likes/tests/phpunit.unit.xml b/extensions/likes/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/likes/tests/phpunit.unit.xml
+++ b/extensions/likes/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/mentions/tests/integration/setup.php b/extensions/mentions/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/mentions/tests/integration/setup.php
+++ b/extensions/mentions/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/mentions/tests/phpunit.integration.xml b/extensions/mentions/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/mentions/tests/phpunit.integration.xml
+++ b/extensions/mentions/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/mentions/tests/phpunit.unit.xml b/extensions/mentions/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/mentions/tests/phpunit.unit.xml
+++ b/extensions/mentions/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/nicknames/tests/integration/setup.php b/extensions/nicknames/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/nicknames/tests/integration/setup.php
+++ b/extensions/nicknames/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/nicknames/tests/phpunit.integration.xml b/extensions/nicknames/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/nicknames/tests/phpunit.integration.xml
+++ b/extensions/nicknames/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/nicknames/tests/phpunit.unit.xml b/extensions/nicknames/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/nicknames/tests/phpunit.unit.xml
+++ b/extensions/nicknames/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/package-manager/tests/integration/setup.php b/extensions/package-manager/tests/integration/setup.php
index 49ccccb84..6b319855d 100644
--- a/extensions/package-manager/tests/integration/setup.php
+++ b/extensions/package-manager/tests/integration/setup.php
@@ -8,11 +8,8 @@
  */
 
 use Flarum\PackageManager\Tests\integration\SetupComposer;
-use Flarum\Testing\integration\Setup\SetupScript;
 
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
 
diff --git a/extensions/package-manager/tests/phpunit.integration.xml b/extensions/package-manager/tests/phpunit.integration.xml
index 89f91a4d1..e467c38a3 100644
--- a/extensions/package-manager/tests/phpunit.integration.xml
+++ b/extensions/package-manager/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/package-manager/tests/phpunit.unit.xml b/extensions/package-manager/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/package-manager/tests/phpunit.unit.xml
+++ b/extensions/package-manager/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/statistics/tests/integration/setup.php b/extensions/statistics/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/statistics/tests/integration/setup.php
+++ b/extensions/statistics/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/statistics/tests/phpunit.integration.xml b/extensions/statistics/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/statistics/tests/phpunit.integration.xml
+++ b/extensions/statistics/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/statistics/tests/phpunit.unit.xml b/extensions/statistics/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/statistics/tests/phpunit.unit.xml
+++ b/extensions/statistics/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/sticky/tests/integration/setup.php b/extensions/sticky/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/sticky/tests/integration/setup.php
+++ b/extensions/sticky/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/sticky/tests/phpunit.integration.xml b/extensions/sticky/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/sticky/tests/phpunit.integration.xml
+++ b/extensions/sticky/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/sticky/tests/phpunit.unit.xml b/extensions/sticky/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/sticky/tests/phpunit.unit.xml
+++ b/extensions/sticky/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/subscriptions/tests/integration/setup.php b/extensions/subscriptions/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/subscriptions/tests/integration/setup.php
+++ b/extensions/subscriptions/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/subscriptions/tests/phpunit.integration.xml b/extensions/subscriptions/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/subscriptions/tests/phpunit.integration.xml
+++ b/extensions/subscriptions/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/subscriptions/tests/phpunit.unit.xml b/extensions/subscriptions/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/subscriptions/tests/phpunit.unit.xml
+++ b/extensions/subscriptions/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/suspend/tests/integration/setup.php b/extensions/suspend/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/suspend/tests/integration/setup.php
+++ b/extensions/suspend/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/suspend/tests/phpunit.integration.xml b/extensions/suspend/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/suspend/tests/phpunit.integration.xml
+++ b/extensions/suspend/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/suspend/tests/phpunit.unit.xml b/extensions/suspend/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/suspend/tests/phpunit.unit.xml
+++ b/extensions/suspend/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/tags/tests/integration/setup.php b/extensions/tags/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/extensions/tags/tests/integration/setup.php
+++ b/extensions/tags/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/extensions/tags/tests/phpunit.integration.xml b/extensions/tags/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/extensions/tags/tests/phpunit.integration.xml
+++ b/extensions/tags/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/extensions/tags/tests/phpunit.unit.xml b/extensions/tags/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/extensions/tags/tests/phpunit.unit.xml
+++ b/extensions/tags/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/framework/core/src/Extension/ExtensionManager.php b/framework/core/src/Extension/ExtensionManager.php
index a8d9fb4d2..01613643d 100644
--- a/framework/core/src/Extension/ExtensionManager.php
+++ b/framework/core/src/Extension/ExtensionManager.php
@@ -73,31 +73,18 @@ class ExtensionManager
                     $composerJsonConfs[$packagePath] = $package;
                 }
 
-                if ($subextPaths = Arr::get($package, 'extra.flarum-subextensions', [])) {
-                    foreach ($subextPaths as $subExtPath) {
-                        $subPackagePath = "$packagePath/$subExtPath";
-                        $conf = json_decode($this->filesystem->get("$subPackagePath/composer.json"), true);
-
-                        if (Arr::get($conf, 'type') === 'flarum-extension') {
-                            $composerJsonConfs[$subPackagePath] = $conf;
-                        }
-                    }
+                if ($subExtConfs = $this->subExtensionConfsFromJson($package, $packagePath)) {
+                    $composerJsonConfs = array_merge($composerJsonConfs, $subExtConfs);
                 }
             }
 
             foreach ($composerJsonConfs as $path => $package) {
                 $installedSet[Arr::get($package, 'name')] = true;
-
-                // Instantiates an Extension object using the package path and composer.json file.
-                $extension = new Extension($path, $package);
-
-                // Per default all extensions are installed if they are registered in composer.
-                $extension->setInstalled(true);
-                $extension->setVersion(Arr::get($package, 'version'));
-
+                $extension = $this->extensionFromJson($package, $path);
                 $extensions->put($extension->getId(), $extension);
             }
 
+            /** @var Extension $extension */
             foreach ($extensions as $extension) {
                 $extension->calculateDependencies($installedSet);
             }
@@ -472,4 +459,36 @@ class ExtensionManager
             'circularDependencies' => $circularDependencies
         ];
     }
+
+    protected function extensionFromJson(array $package, string $path): Extension
+    {
+        // Instantiates an Extension object using the package path and composer.json file.
+        $extension = new Extension($path, $package);
+
+        // Per default all extensions are installed if they are registered in composer.
+        $extension->setInstalled(true);
+        $extension->setVersion(Arr::get($package, 'version', '0.0'));
+
+        return $extension;
+    }
+
+    protected function subExtensionConfsFromJson(array $package, string $packagePath): ?array
+    {
+        if (! ($subExtPaths = Arr::get($package, 'extra.flarum-subextensions', []))) {
+            return null;
+        }
+
+        $subExtConfs = [];
+
+        foreach ($subExtPaths as $subExtPath) {
+            $subPackagePath = "$packagePath/$subExtPath";
+            $conf = json_decode($this->filesystem->get("$subPackagePath/composer.json"), true);
+
+            if (Arr::get($conf, 'type') === 'flarum-extension') {
+                $subExtConfs[$subPackagePath] = $conf;
+            }
+        }
+
+        return $subExtConfs;
+    }
 }
diff --git a/framework/core/tests/integration/setup.php b/framework/core/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/framework/core/tests/integration/setup.php
+++ b/framework/core/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/framework/core/tests/phpunit.integration.xml b/framework/core/tests/phpunit.integration.xml
index 90fbbff37..7319d929a 100644
--- a/framework/core/tests/phpunit.integration.xml
+++ b/framework/core/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/framework/core/tests/phpunit.unit.xml b/framework/core/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/framework/core/tests/phpunit.unit.xml
+++ b/framework/core/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/php-packages/testing/bootstrap/monorepo.php b/php-packages/testing/bootstrap/monorepo.php
new file mode 100644
index 000000000..4d25d257b
--- /dev/null
+++ b/php-packages/testing/bootstrap/monorepo.php
@@ -0,0 +1,42 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+/*
+|
+| This is specific to a monorepo setup. If you're using a single
+| repository for your extension, checkout the extension skeleton
+| at https://github.com/flarum/cli/tree/main/boilerplate/skeleton/extension.
+|
+| ---------------------------------------------------------------
+|
+| We symlink local vendor bins to the framework vendor bin
+| to be able to run scripts from the extension directory.
+|
+| We also use a `FLARUM_TEST_VENDOR_PATH` environment variable
+| to tell each extension where to find the framework vendor,
+| instead of a SetupScript property, because it is also needed
+| when running the tests.
+|
+*/
+
+$monorepoVendor = __DIR__.'/../../../vendor';
+
+// The root directory of the extension where tests are run from.
+$localVendor = getcwd().'/vendor';
+
+if (! file_exists("$localVendor/bin")) {
+    mkdir("$localVendor");
+    symlink("$monorepoVendor/bin", "$localVendor/bin");
+}
+
+require $monorepoVendor.'/autoload.php';
+
+putenv('FLARUM_TEST_VENDOR_PATH='.$monorepoVendor);
+
+return new Flarum\Testing\integration\Setup\SetupScript();
diff --git a/php-packages/testing/src/integration/Extension/ExtensionManagerIncludeCurrent.php b/php-packages/testing/src/integration/Extension/ExtensionManagerIncludeCurrent.php
index 23c2787f3..46787abb2 100644
--- a/php-packages/testing/src/integration/Extension/ExtensionManagerIncludeCurrent.php
+++ b/php-packages/testing/src/integration/Extension/ExtensionManagerIncludeCurrent.php
@@ -54,21 +54,11 @@ class ExtensionManagerIncludeCurrent extends ExtensionManager
         $extensions = parent::getExtensions();
 
         $package = json_decode($this->filesystem->get($this->paths->vendor.'/../composer.json'), true);
+        $packagePath = $this->paths->vendor.'/../';
 
-        if (Arr::get($package, 'type') === 'flarum-extension') {
-            $current = new Extension($this->paths->vendor.'/../', $package);
-            $current->setInstalled(true);
-            $current->setVersion(Arr::get($package, 'version', '0.0'));
-            $current->calculateDependencies([]);
+        $extensions = $this->includeCurrentExtension($extensions, $package, $packagePath);
 
-            $extensions->put($current->getId(), $current);
-
-            $this->extensions = $extensions->sortBy(function ($extension) {
-                return $extension->composerJsonAttribute('extra.flarum-extension.title');
-            });
-        }
-
-        return $this->extensions;
+        return $this->extensions = $this->includeMonorepoExtensions($extensions, $package, $packagePath);
     }
 
     /**
@@ -111,4 +101,36 @@ class ExtensionManagerIncludeCurrent extends ExtensionManager
 
         return new FilesystemAdapter(new \League\Flysystem\Filesystem($adapter), $adapter);
     }
+
+    protected function includeCurrentExtension(Collection $extensions, $package, string $packagePath): Collection
+    {
+        if (Arr::get($package, 'type') === 'flarum-extension') {
+            $current = new Extension($packagePath, $package);
+            $current->setInstalled(true);
+            $current->setVersion(Arr::get($package, 'version', '0.0'));
+            $current->calculateDependencies([]);
+
+            $extensions->put($current->getId(), $current);
+
+            $extensions = $extensions->sortBy(function ($extension, $name) {
+                return $extension->composerJsonAttribute('extra.flarum-extension.title');
+            });
+        }
+
+        return $extensions;
+    }
+
+    /**
+     * Allows symlinking the vendor directory in extensions when running tests on monorepos.
+     */
+    protected function includeMonorepoExtensions(Collection $extensions, $package, string $packagePath): Collection
+    {
+        foreach ($this->subExtensionConfsFromJson($package, $packagePath) ?? [] as $path => $package) {
+            $extension = $this->extensionFromJson($package, $path);
+            $extension->calculateDependencies([]);
+            $extensions->put($extension->getId(), $extension);
+        }
+
+        return $extensions;
+    }
 }
diff --git a/php-packages/testing/src/integration/Setup/SetupScript.php b/php-packages/testing/src/integration/Setup/SetupScript.php
index f9c75afb2..e6d70a9ea 100644
--- a/php-packages/testing/src/integration/Setup/SetupScript.php
+++ b/php-packages/testing/src/integration/Setup/SetupScript.php
@@ -116,7 +116,7 @@ class SetupScript
                 'base' => $tmp,
                 'public' => "$tmp/public",
                 'storage' => "$tmp/storage",
-                'vendor' => getcwd().'/vendor',
+                'vendor' => getenv('FLARUM_TEST_VENDOR_PATH') ?: getcwd().'/vendor',
             ])
         );
 
diff --git a/php-packages/testing/src/integration/TestCase.php b/php-packages/testing/src/integration/TestCase.php
index fa2660971..a0913ab2f 100644
--- a/php-packages/testing/src/integration/TestCase.php
+++ b/php-packages/testing/src/integration/TestCase.php
@@ -64,7 +64,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase
                     'base' => $tmp,
                     'public' => "$tmp/public",
                     'storage' => "$tmp/storage",
-                    'vendor' => getcwd().'/vendor',
+                    'vendor' => getenv('FLARUM_TEST_VENDOR_PATH') ?: getcwd().'/vendor',
                 ]),
                 new Config($config)
             );
diff --git a/php-packages/testing/tests/tests/integration/setup.php b/php-packages/testing/tests/tests/integration/setup.php
index 67039c083..96caab5fe 100644
--- a/php-packages/testing/tests/tests/integration/setup.php
+++ b/php-packages/testing/tests/tests/integration/setup.php
@@ -7,10 +7,6 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Testing\integration\Setup\SetupScript;
-
-require __DIR__.'/../../vendor/autoload.php';
-
-$setup = new SetupScript();
+$setup = require __DIR__.'/../../../../php-packages/testing/bootstrap/monorepo.php';
 
 $setup->run();
diff --git a/php-packages/testing/tests/tests/phpunit.integration.xml b/php-packages/testing/tests/tests/phpunit.integration.xml
index 23afc237d..f9fbdf591 100644
--- a/php-packages/testing/tests/tests/phpunit.integration.xml
+++ b/php-packages/testing/tests/tests/phpunit.integration.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="true"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>
diff --git a/php-packages/testing/tests/tests/phpunit.unit.xml b/php-packages/testing/tests/tests/phpunit.unit.xml
index d3a4a3e3d..66262dd9f 100644
--- a/php-packages/testing/tests/tests/phpunit.unit.xml
+++ b/php-packages/testing/tests/tests/phpunit.unit.xml
@@ -10,6 +10,7 @@
     convertWarningsToExceptions="true"
     processIsolation="false"
     stopOnFailure="false"
+    bootstrap="../../../php-packages/testing/bootstrap/monorepo.php"
 >
     <coverage processUncoveredFiles="true">
         <include>