diff --git a/library/spdm_requester_lib/libspdm_req_get_capabilities.c b/library/spdm_requester_lib/libspdm_req_get_capabilities.c
index 95e05cd14bc..abff87e3ca1 100644
--- a/library/spdm_requester_lib/libspdm_req_get_capabilities.c
+++ b/library/spdm_requester_lib/libspdm_req_get_capabilities.c
@@ -79,7 +79,11 @@ static bool validate_responder_capability(uint32_t capabilities_flag, uint8_t ve
         }
 
         /* Checks that originate from key exchange capabilities. */
-        if ((key_ex_cap == 0) && (psk_cap == 0)) {
+        if ((key_ex_cap == 1) || (psk_cap != 0)) {
+            if ((mac_cap == 0) && (encrypt_cap == 0)) {
+                return false;
+            }
+        } else {
             if ((mac_cap == 1) || (encrypt_cap == 1) || (handshake_in_the_clear_cap == 1) ||
                 (hbeat_cap == 1) || (key_upd_cap == 1)) {
                 return false;
diff --git a/library/spdm_responder_lib/libspdm_rsp_capabilities.c b/library/spdm_responder_lib/libspdm_rsp_capabilities.c
index 3d7986d18a2..2edbf0ea3fa 100644
--- a/library/spdm_responder_lib/libspdm_rsp_capabilities.c
+++ b/library/spdm_responder_lib/libspdm_rsp_capabilities.c
@@ -71,7 +71,11 @@ static bool libspdm_check_request_flag_compatibility(uint32_t capabilities_flag,
         }
 
         /* Checks that originate from key exchange capabilities. */
-        if ((key_ex_cap == 0) && (psk_cap == 0)) {
+        if ((key_ex_cap == 1) || (psk_cap != 0)) {
+            if ((mac_cap == 0) && (encrypt_cap == 0)) {
+                return false;
+            }
+        } else {
             if ((mac_cap == 1) || (encrypt_cap == 1) || (handshake_in_the_clear_cap == 1) ||
                 (hbeat_cap == 1) || (key_upd_cap == 1)) {
                 return false;
diff --git a/unit_test/test_spdm_requester/error_test/get_capabilities_err.c b/unit_test/test_spdm_requester/error_test/get_capabilities_err.c
index 46a94ecee56..842872aca02 100644
--- a/unit_test/test_spdm_requester/error_test/get_capabilities_err.c
+++ b/unit_test/test_spdm_requester/error_test/get_capabilities_err.c
@@ -592,7 +592,33 @@ static libspdm_return_t libspdm_requester_get_capabilities_test_receive_message(
     }
         return LIBSPDM_STATUS_SUCCESS;
 
-    case 0x14:
+    case 0x14: {
+        spdm_capabilities_response_t *spdm_response;
+        size_t spdm_response_size;
+        size_t transport_header_size;
+
+        spdm_response_size = sizeof(spdm_capabilities_response_t);
+        transport_header_size = LIBSPDM_TEST_TRANSPORT_HEADER_SIZE;
+        spdm_response = (void *)((uint8_t *)*response + transport_header_size);
+
+        libspdm_zero_mem(spdm_response, spdm_response_size);
+        spdm_response->header.spdm_version = SPDM_MESSAGE_VERSION_11;
+        spdm_response->header.request_response_code = SPDM_CAPABILITIES;
+        spdm_response->header.param1 = 0;
+        spdm_response->header.param2 = 0;
+        spdm_response->ct_exponent = 0;
+        spdm_response->flags =
+            LIBSPDM_DEFAULT_CAPABILITY_RESPONSE_FLAG_VERSION_11 &
+            (0xFFFFFFFF ^
+             (SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_ENCRYPT_CAP |
+              SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_MAC_CAP |
+              SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_HANDSHAKE_IN_THE_CLEAR_CAP));
+
+        libspdm_transport_test_encode_message(spdm_context, NULL, false,
+                                              false, spdm_response_size,
+                                              spdm_response,
+                                              response_size, response);
+    }
         return LIBSPDM_STATUS_SUCCESS;
 
     case 0x15:
@@ -1394,6 +1420,22 @@ static void libspdm_test_requester_get_capabilities_err_case19(void **state)
 
 static void libspdm_test_requester_get_capabilities_err_case20(void **state)
 {
+    libspdm_return_t status;
+    libspdm_test_context_t *spdm_test_context;
+    libspdm_context_t *spdm_context;
+
+    spdm_test_context = *state;
+    spdm_context = spdm_test_context->spdm_context;
+    spdm_test_context->case_id = 0x14;
+    spdm_context->connection_info.version = SPDM_MESSAGE_VERSION_11 <<
+                                            SPDM_VERSION_NUMBER_SHIFT_BIT;
+    spdm_context->connection_info.connection_state = LIBSPDM_CONNECTION_STATE_AFTER_VERSION;
+    libspdm_reset_message_a(spdm_context);
+
+    spdm_context->local_context.capability.ct_exponent = 0;
+    spdm_context->local_context.capability.flags = LIBSPDM_DEFAULT_CAPABILITY_FLAG_VERSION_11;
+    status = libspdm_get_capabilities(spdm_context);
+    assert_int_equal(status, LIBSPDM_STATUS_INVALID_MSG_FIELD);
 }
 
 static void libspdm_test_requester_get_capabilities_err_case21(void **state)
diff --git a/unit_test/test_spdm_responder/capabilities.c b/unit_test/test_spdm_responder/capabilities.c
index d0129d44ac6..0948e9044cd 100644
--- a/unit_test/test_spdm_responder/capabilities.c
+++ b/unit_test/test_spdm_responder/capabilities.c
@@ -837,10 +837,64 @@ void libspdm_test_responder_capabilities_case15(void **state)
 
 void libspdm_test_responder_capabilities_case16(void **state)
 {
+    libspdm_return_t status;
+    libspdm_test_context_t *spdm_test_context;
+    libspdm_context_t *spdm_context;
+    size_t response_size;
+    uint8_t response[LIBSPDM_MAX_SPDM_MSG_SIZE];
+    spdm_capabilities_response_t *spdm_response;
+
+    spdm_test_context = *state;
+    spdm_context = spdm_test_context->spdm_context;
+    spdm_test_context->case_id = 0x10;
+    spdm_context->connection_info.connection_state =
+        LIBSPDM_CONNECTION_STATE_AFTER_VERSION;
+
+    response_size = sizeof(response);
+    status = libspdm_get_response_capabilities(
+        spdm_context, m_libspdm_get_capabilities_request12_size,
+        &m_libspdm_get_capabilities_request12, &response_size, response);
+    assert_int_equal(status, LIBSPDM_STATUS_SUCCESS);
+    assert_int_equal(response_size, sizeof(spdm_error_response_t));
+    spdm_response = (void *)response;
+    assert_int_equal(m_libspdm_get_capabilities_request12.header.spdm_version,
+                     spdm_response->header.spdm_version);
+    assert_int_equal(spdm_response->header.request_response_code,
+                     SPDM_ERROR);
+    assert_int_equal(spdm_response->header.param1,
+                     SPDM_ERROR_CODE_INVALID_REQUEST);
+    assert_int_equal(spdm_response->header.param2, 0);
 }
 
 void libspdm_test_responder_capabilities_case17(void **state)
 {
+    libspdm_return_t status;
+    libspdm_test_context_t *spdm_test_context;
+    libspdm_context_t *spdm_context;
+    size_t response_size;
+    uint8_t response[LIBSPDM_MAX_SPDM_MSG_SIZE];
+    spdm_capabilities_response_t *spdm_response;
+
+    spdm_test_context = *state;
+    spdm_context = spdm_test_context->spdm_context;
+    spdm_test_context->case_id = 0x11;
+    spdm_context->connection_info.connection_state =
+        LIBSPDM_CONNECTION_STATE_AFTER_VERSION;
+
+    response_size = sizeof(response);
+    status = libspdm_get_response_capabilities(
+        spdm_context, m_libspdm_get_capabilities_request13_size,
+        &m_libspdm_get_capabilities_request13, &response_size, response);
+    assert_int_equal(status, LIBSPDM_STATUS_SUCCESS);
+    assert_int_equal(response_size, sizeof(spdm_error_response_t));
+    spdm_response = (void *)response;
+    assert_int_equal(m_libspdm_get_capabilities_request13.header.spdm_version,
+                     spdm_response->header.spdm_version);
+    assert_int_equal(spdm_response->header.request_response_code,
+                     SPDM_ERROR);
+    assert_int_equal(spdm_response->header.param1,
+                     SPDM_ERROR_CODE_INVALID_REQUEST);
+    assert_int_equal(spdm_response->header.param2, 0);
 }
 
 void libspdm_test_responder_capabilities_case18(void **state)
@@ -1173,9 +1227,9 @@ int libspdm_responder_capabilities_test_main(void)
         cmocka_unit_test(libspdm_test_responder_capabilities_case14),
         /* mac_cap set and key_ex_cap and psk_cap cleared (mac_cap demands key_ex_cap or psk_cap to be set)*/
         cmocka_unit_test(libspdm_test_responder_capabilities_case15),
-        /* Open test case */
+        /* key_ex_cap set and encrypt_cap and mac_cap cleared (key_ex_cap demands encrypt_cap or mac_cap to be set)*/
         cmocka_unit_test(libspdm_test_responder_capabilities_case16),
-        /* Open test case */
+        /* psk_cap set and encrypt_cap and mac_cap cleared (psk_cap demands encrypt_cap or mac_cap to be set)*/
         cmocka_unit_test(libspdm_test_responder_capabilities_case17),
         /* encap_cap cleared and MUT_AUTH set (MUT_AUTH demands encap_cap to be set)*/
         cmocka_unit_test(libspdm_test_responder_capabilities_case18),