diff --git a/cekit/tools.py b/cekit/tools.py
index a53b9ec..9aaba1e 100644
--- a/cekit/tools.py
+++ b/cekit/tools.py
@@ -352,6 +352,14 @@ class DependencyHandler(object):
         self._handle_dependencies(
             DependencyHandler.EXTERNAL_CORE_DEPENDENCIES)
 
+        try:
+            import certifi  # pylint: disable=unused-import
+            LOGGER.warning(("The certifi library (https://certifi.io/) was found, depending on the operating " +
+                            "system configuration this may result in certificate validation issues"))
+            LOGGER.warning("Certificate Authority (CA) bundle in use: '{}'".format(certifi.where()))
+        except ImportError:
+            pass
+
     def handle(self, o):
         """
         Handles dependencies from selected object. If the object has 'dependencies' method,

diff --git a/tests/test_unit_tools.py b/tests/test_unit_tools.py
index 9ac8561..fba8b71 100644
--- a/tests/test_unit_tools.py
+++ b/tests/test_unit_tools.py
@@ -1,6 +1,7 @@
 import logging
 import pytest
 import subprocess
+import sys
 import yaml
 
 from contextlib import contextmanager
@@ -550,3 +551,25 @@ def test_dependency_handler_check_for_executable_with_executable_fail_with_packa
 
         with pytest.raises(CekitError, match=r"^CEKit dependency: 'xyz' was not found, please provide the 'xyz-aaa' executable. To satisfy this requirement you can install the 'package-xyz' package.$"):
             handler._check_for_executable('xyz', 'xyz-aaa', 'package-xyz')
+
+
+def test_handle_core_dependencies_no_certifi(mocker, caplog):
+    sys.modules['certifi'] = None
+
+    with mocked_dependency_handler(mocker) as handler:
+        handler.handle_core_dependencies()
+
+    assert "The certifi library (https://certifi.io/) was found, depending on the operating system configuration this may result in certificate validation issues" not in caplog.text
+
+
+def test_handle_core_dependencies_with_certifi(mocker, caplog):
+    mock_certifi = mocker.Mock()
+    mock_certifi.where.return_value = 'a/path.pem'
+
+    sys.modules['certifi'] = mock_certifi
+
+    with mocked_dependency_handler(mocker) as handler:
+        handler.handle_core_dependencies()
+
+    assert "The certifi library (https://certifi.io/) was found, depending on the operating system configuration this may result in certificate validation issues" in caplog.text
+    assert "Certificate Authority (CA) bundle in use: 'a/path.pem'" in caplog.text

Try to detect certifi package installs and warn user if custom installation is found
The certifi library when installed locally provides a custom certificate store that can override the globally provided setting. We should try to find if certifi is installed and if yes, we should warn the user that certificate-related issues may appear.

We probably should do this only when `--redhat` switch is used.
tests/test_unit_tools.py::test_handle_core_dependencies_with_certifi
tests/test_unit_tools.py::test_merging_description_image tests/test_unit_tools.py::test_merging_description_modules tests/test_unit_tools.py::test_merging_description_override tests/test_unit_tools.py::test_merging_plain_descriptors tests/test_unit_tools.py::test_merging_emdedded_descriptors tests/test_unit_tools.py::test_merging_plain_lists tests/test_unit_tools.py::test_merging_plain_list_of_list tests/test_unit_tools.py::test_merging_list_of_descriptors tests/test_unit_tools.py::test_merge_run_cmd tests/test_unit_tools.py::test_get_brew_url tests/test_unit_tools.py::test_get_brew_url_when_build_was_removed tests/test_unit_tools.py::test_get_brew_url_no_kerberos tests/test_unit_tools.py::test_get_brew_url_with_artifact_containing_dot tests/test_unit_tools.py::test_dependency_handler_init_on_unknown_env_with_os_release_file tests/test_unit_tools.py::test_dependency_handler_on_rhel_7 tests/test_unit_tools.py::test_dependency_handler_on_rhel_8 tests/test_unit_tools.py::test_dependency_handler_init_on_known_env tests/test_unit_tools.py::test_dependency_handler_init_on_unknown_env_without_os_release_file tests/test_unit_tools.py::test_dependency_handler_handle_dependencies_doesnt_fail_without_deps tests/test_unit_tools.py::test_dependency_handler_handle_dependencies_with_executable_only tests/test_unit_tools.py::test_dependency_handler_handle_dependencies_with_executable_only_failed tests/test_unit_tools.py::test_dependency_handler_handle_dependencies_with_executable_and_package_on_known_platform tests/test_unit_tools.py::test_dependency_handler_handle_dependencies_with_platform_specific_package tests/test_unit_tools.py::test_dependency_handler_check_for_executable_with_executable_only tests/test_unit_tools.py::test_dependency_handler_check_for_executable_with_executable_fail tests/test_unit_tools.py::test_dependency_handler_check_for_executable_with_executable_fail_with_package tests/test_unit_tools.py::test_handle_core_dependencies_no_certifi