diff --git a/tests/libtransport/config.cpp b/tests/libtransport/config.cpp
index fea9ada11c53bb5d50a556af3ae635710c23c7a6..8062b6e5829de3cd96853d9610abb22d3e2407db 100644
--- a/tests/libtransport/config.cpp
+++ b/tests/libtransport/config.cpp
@@ -16,6 +16,7 @@ using namespace Transport;
 class ConfigTest : public CPPUNIT_NS :: TestFixture{
 	CPPUNIT_TEST_SUITE(ConfigTest);
 	CPPUNIT_TEST(setStringTwice);
+	CPPUNIT_TEST(setUnknownBool);
 	CPPUNIT_TEST(updateBackendConfig);
 	CPPUNIT_TEST(updateBackendConfigJIDEscaping);
 	CPPUNIT_TEST(unregisteredList);
@@ -40,6 +41,14 @@ class ConfigTest : public CPPUNIT_NS :: TestFixture{
 		CPPUNIT_ASSERT_EQUAL(std::string("localhost"), CONFIG_STRING(&cfg, "service.jids"));
 	}
 
+	void setUnknownBool() {
+		char *argv[3] = {"binary", "--service.jids=localhost", NULL};
+		Config cfg(2, argv);
+		std::istringstream ifs("service.irc_send_pass = 1\n");
+		cfg.load(ifs);
+		CPPUNIT_ASSERT_EQUAL(true, CONFIG_BOOL_DEFAULTED(&cfg, "service.irc_send_pass", false));
+	}
+
 	void updateBackendConfig() {
 		Config cfg;
 		CPPUNIT_ASSERT(!cfg.hasKey("registration.needPassword"));