diff --git a/pam/auth_client_test.cc b/pam/auth_client_test.cc
index 818939a9b5200ee4afc1336619a6c281f1bd47fd..da49a473921d24c4e5c445264c8848a83577dea5 100644
--- a/pam/auth_client_test.cc
+++ b/pam/auth_client_test.cc
@@ -59,6 +59,17 @@ TEST_F(AuthClientTest, AuthOK) {
                            << ", server=" << server;
 }
 
+TEST_F(AuthClientTest, AuthFail) {
+  int result;
+
+  result = auth_client_set_certificate(ac, ssl_ca, ssl_cert, ssl_key);
+  EXPECT_EQ(AC_OK, result) << "set_certificate() error: " << auth_client_strerror(result);
+
+  result = auth_client_authenticate(ac, "user", "bad_password", NULL, "127.0.0.1");
+  EXPECT_NE(AC_OK, result) << "authenticate() didn't fail"
+                           << ", server=" << server;
+}
+
 TEST_F(AuthClientTest, SSLFailsWithBadCertificate) {
   int result;