diff --git a/unit_test/main_tests/main_platform_test.py b/unit_test/main_tests/main_platform_test.py
index 41ca1373..009fb1b4 100644
--- a/unit_test/main_tests/main_platform_test.py
+++ b/unit_test/main_tests/main_platform_test.py
@@ -12,6 +12,7 @@ def test_unknown_platform_non_ci(monkeypatch, capsys):
     monkeypatch.delenv('BITRISE_BUILD_NUMBER', raising=False)
     monkeypatch.delenv('AZURE_HTTP_USER_AGENT', raising=False)
     monkeypatch.delenv('GITHUB_WORKFLOW', raising=False)
+    monkeypatch.delenv('CIBW_PLATFORM', raising=False)
 
     with pytest.raises(SystemExit) as exit:
         main()
@@ -25,6 +26,7 @@ def test_unknown_platform_non_ci(monkeypatch, capsys):
 def test_unknown_platform_on_ci(monkeypatch, capsys):
     monkeypatch.setenv('CI', 'true')
     monkeypatch.setattr(sys, 'platform', 'nonexistent')
+    monkeypatch.delenv('CIBW_PLATFORM', raising=False)
 
     with pytest.raises(SystemExit) as exit:
         main()