diff --git a/tests/unit-tests/security/tpm/back-end.t.cpp b/tests/unit-tests/security/tpm/back-end.t.cpp
index ad8e39c..f118099 100644
--- a/tests/unit-tests/security/tpm/back-end.t.cpp
+++ b/tests/unit-tests/security/tpm/back-end.t.cpp
@@ -221,6 +221,8 @@
 
   tpm.importKey(keyName, privateKeyBuffer->data(), privateKeyBuffer->size(), password.c_str(), password.size());
   BOOST_CHECK_EQUAL(tpm.hasKey(keyName), true);
+  BOOST_CHECK_THROW(tpm.importKey(keyName, privateKeyBuffer->data(), privateKeyBuffer->size(), password.c_str(), password.size()),
+                    BackEnd::Error);
 
   ConstBufferPtr exportedKey = tpm.exportKey(keyName, password.c_str(), password.size());
   BOOST_CHECK_EQUAL(tpm.hasKey(keyName), true);
@@ -236,6 +238,7 @@
 
   tpm.deleteKey(keyName);
   BOOST_CHECK_EQUAL(tpm.hasKey(keyName), false);
+  BOOST_CHECK_THROW(tpm.exportKey(keyName, password.c_str(), password.size()), BackEnd::Error);
 }
 
 BOOST_AUTO_TEST_CASE(RandomKeyId)