diff --git a/tests/test_rpm_verifier.py b/tests/test_rpm_verifier.py
index dc6f3c0..60f1e6a 100644
--- a/tests/test_rpm_verifier.py
+++ b/tests/test_rpm_verifier.py
@@ -2,6 +2,7 @@
 from pathlib import Path
 from subprocess import CalledProcessError
 from textwrap import dedent
+from typing import Callable
 from unittest.mock import MagicMock, call, create_autospec, sentinel
 
 import pytest
@@ -355,24 +356,34 @@ def mock_image_processor(self, monkeypatch: MonkeyPatch) -> MagicMock:
         return mock
 
     @pytest.fixture()
-    def mock_generate_output(self, monkeypatch: MonkeyPatch) -> MagicMock:
-        """Monkey-patched generate_output"""
-        mock = create_autospec(generate_output, return_value=(False, ""))
-        monkeypatch.setattr(rpm_verifier, generate_output.__name__, mock)
-        return mock
+    def create_generate_output_mock(
+        self, monkeypatch: MonkeyPatch
+    ) -> Callable[[bool], MagicMock]:
+        """Create a generate_output mock with different results according to
+        the `fail_unsigned` flag"""
+
+        def _mock_generate_output(fail: bool = False) -> MagicMock:
+            """Monkey-patched generate_output"""
+            mock = create_autospec(generate_output, return_value=(fail, ""))
+            monkeypatch.setattr(rpm_verifier, generate_output.__name__, mock)
+            return mock
+
+        return _mock_generate_output
 
     def test_main(
         self,
-        mock_generate_output: MagicMock,
+        create_generate_output_mock: MagicMock,
         mock_image_processor: MagicMock,
     ) -> None:
         """Test call to rpm_verifier.py main function"""
+        fail_on_unsigned_rpms: bool = False
+        generate_output_mock = create_generate_output_mock(fail=fail_on_unsigned_rpms)
         rpm_verifier.main(  # pylint: disable=no-value-for-parameter
             args=[
                 "--input",
                 "img1",
                 "--fail-unsigned",
-                "true",
+                fail_on_unsigned_rpms,
                 "--workdir",
                 "some/path",
             ],
@@ -381,5 +392,32 @@ def test_main(
         )
 
         assert mock_image_processor.return_value.call_count == 1
+        generate_output_mock.assert_called_once_with(
+            [sentinel.output], fail_on_unsigned_rpms
+        )
         mock_image_processor.return_value.assert_has_calls([call("img1")])
-        mock_generate_output.assert_called_once_with([sentinel.output], True)
+
+    def test_main_fail_on_unsigned_rpm(
+        self,
+        create_generate_output_mock: MagicMock,
+        mock_image_processor: MagicMock,
+    ) -> None:
+        """Test call to rpm_verifier.py main function fails
+        when whe 'fail-unsigned' flag is used and there are unsigned RPMs
+        """
+        fail_on_unsigned_rpms: bool = True
+        create_generate_output_mock(fail=fail_on_unsigned_rpms)
+        with pytest.raises(SystemExit):
+            rpm_verifier.main(  # pylint: disable=no-value-for-parameter
+                args=[
+                    "--input",
+                    "img1",
+                    "--fail-unsigned",
+                    fail_on_unsigned_rpms,
+                    "--workdir",
+                    "some/path",
+                ],
+                obj={},
+                standalone_mode=False,
+            )
+        assert mock_image_processor.return_value.call_count == 1