diff --git a/pulpcore/tests/functional/api/using_plugin/constants.py b/pulpcore/tests/functional/api/using_plugin/constants.py
index dadcda0fdb8..1dd515532ca 100644
--- a/pulpcore/tests/functional/api/using_plugin/constants.py
+++ b/pulpcore/tests/functional/api/using_plugin/constants.py
@@ -65,3 +65,30 @@
 
 FILE2_URL = urljoin(FILE2_FIXTURE_URL, '1.iso')
 """The URL to an ISO file at :data:`FILE2_FIXTURE_URL`."""
+
+RPM_UNSIGNED_FIXTURE_URL = urljoin(PULP_FIXTURES_BASE_URL, 'rpm-unsigned/')
+"""The URL to a repository with unsigned RPM packages."""
+
+RPM_REMOTE_PATH = urljoin(BASE_REMOTE_PATH, 'rpm/rpm/')
+
+RPM_PACKAGE_CONTENT_NAME = 'rpm.package'
+
+RPM_UPDATE_CONTENT_NAME = 'rpm.update'
+
+RPM_PACKAGES_COUNT = 35
+"""The number of packages available at
+:data:`RPM_SIGNED_FIXTURE_URL` and :data:`RPM_UNSIGNED_FIXTURE_URL`
+"""
+
+RPM_UPDATE_COUNT = 4
+"""The number of updated record units."""
+
+RPM_FIXTURE_SUMMARY = {
+    RPM_PACKAGE_CONTENT_NAME: RPM_PACKAGES_COUNT,
+    RPM_UPDATE_CONTENT_NAME: RPM_UPDATE_COUNT
+}
+"""The breakdown of how many of each type of content unit are present in the
+standard repositories, i.e. :data:`RPM_SIGNED_FIXTURE_URL` and
+:data:`RPM_UNSIGNED_FIXTURE_URL`.  This matches the format output by the
+"content_summary" field on "../repositories/../versions/../".
+"""
diff --git a/pulpcore/tests/functional/api/using_plugin/test_sync_multiple_plugins.py b/pulpcore/tests/functional/api/using_plugin/test_sync_multiple_plugins.py
new file mode 100644
index 00000000000..4aa95ec8d79
--- /dev/null
+++ b/pulpcore/tests/functional/api/using_plugin/test_sync_multiple_plugins.py
@@ -0,0 +1,96 @@
+# coding=utf-8
+"""Tests related to multiple plugins."""
+import os
+import unittest
+
+from pulp_smash import api, config
+from pulp_smash.pulp3.constants import REPO_PATH
+from pulp_smash.pulp3.utils import (
+    gen_remote,
+    gen_repo,
+    get_added_content_summary,
+    get_content_summary,
+    get_removed_content_summary,
+    sync,
+)
+
+from pulpcore.tests.functional.api.using_plugin.constants import (
+    FILE_FIXTURE_MANIFEST_URL,
+    FILE_FIXTURE_SUMMARY,
+    FILE_REMOTE_PATH,
+    RPM_FIXTURE_SUMMARY,
+    RPM_REMOTE_PATH,
+    RPM_UNSIGNED_FIXTURE_URL,
+)
+from pulpcore.tests.functional.utils import skip_if
+
+
+class SyncMultiplePlugins(unittest.TestCase):
+    """Sync repositories with the multiple plugins in the same repo."""
+
+    @classmethod
+    def setUpClass(cls):
+        """Create class-wide variables."""
+        cls.cfg = config.get_config()
+        cls.client = api.Client(cls.cfg, api.json_handler)
+        cls.travis = 'TRAVIS' in os.environ
+
+    @skip_if(bool, 'travis', True)
+    def test_mirror_sync(self):
+        """Sync multiple plugin into the same repo with mirror as `True`.
+
+        This test targets the following issue: 4448
+
+        * `<https://pulp.plan.io/issues/4448>`_
+
+        This test does the following:
+
+        1. Create a repo.
+        2. Create two remotes
+            a. RPM remote
+            b. File remote
+        3. Sync the repo with RPM remote.
+        4. Sync the repo with File remote with ``Mirror=True``.
+        5. Verify whether the content in the latest version of the repo
+           has only File content and RPM content is deleted.
+        """
+        # Step 1
+        repo = self.client.post(REPO_PATH, gen_repo())
+        self.addCleanup(self.client.delete, repo['_href'])
+
+        # Step 2
+        rpm_remote_body = gen_remote(url=RPM_UNSIGNED_FIXTURE_URL)
+        rpm_remote = self.client.post(RPM_REMOTE_PATH, rpm_remote_body)
+        self.addCleanup(self.client.delete, rpm_remote['_href'])
+
+        file_remote_body = gen_remote(url=FILE_FIXTURE_MANIFEST_URL)
+        file_remote = self.client.post(FILE_REMOTE_PATH, file_remote_body)
+        self.addCleanup(self.client.delete, file_remote['_href'])
+
+        # Step 3
+        sync(self.cfg, rpm_remote, repo)
+        repo = self.client.get(repo['_href'])
+        self.assertIsNotNone(repo['_latest_version_href'])
+        self.assertDictEqual(
+            get_added_content_summary(repo),
+            RPM_FIXTURE_SUMMARY
+        )
+
+        # Step 4
+        sync(self.cfg, file_remote, repo, mirror=True)
+        repo = self.client.get(repo['_href'])
+        self.assertIsNotNone(repo['_latest_version_href'])
+        self.assertDictEqual(
+            get_added_content_summary(repo),
+            FILE_FIXTURE_SUMMARY
+        )
+
+        # Step 5
+        self.assertDictEqual(
+            get_content_summary(repo),
+            FILE_FIXTURE_SUMMARY
+        )
+        self.assertDictEqual(
+            get_removed_content_summary(repo),
+            RPM_FIXTURE_SUMMARY
+        )