diff --git a/tests/suites/test_suite_ecp.data b/tests/suites/test_suite_ecp.data
index d08ce0f99..83abd44d4 100644
--- a/tests/suites/test_suite_ecp.data
+++ b/tests/suites/test_suite_ecp.data
@@ -1520,3 +1520,7 @@ ecp_add_sub #48 MBEDTLS_ECP_MOD_SCALAR(MBEDTLS_ECP_DP_CURVE448)
 depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
 ecp_mod_add_sub:"0000000000000003f7defb1691e8e3b705620733deaaddd33a760e17a4e9ba333445533fcd71d42a6d00e3468c946b0ff353728c6173d944afbfae4877c606f":"0000000000000003f96c1d081a3cfe300dc4c27fa2ebbc37396957d4bf81156d86b88de3a9312ca5be57d93fa3549b71895aa36bd5231f38146a2f0970425b":MBEDTLS_ECP_DP_CURVE448:MBEDTLS_ECP_MOD_SCALAR
 
+#Add one test case that the sum of upper half and lower half of the X is equal to "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+ecp_mod_p448 #1 - f4ae65e920a63ac1f2b64df6dff07870c9d531ae72a47403063238da1a1fe3f9d6a179fa50f96cd4aff9261aa92c0e6f17ec940639bc2ccd0B519A16DF59C53E0D49B209200F878F362ACE518D5B8BFCF9CDC725E5E01C06295E8605AF06932B5006D9E556D3F190E8136BF9C643D332 mod fffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffffffffffffffffffffffffffffffffffffffffffffffffffff
+depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
+ecp_mod_p448:"fffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffffffffffffffffffffffffffffffffffffffffffffffffffff":"f4ae65e920a63ac1f2b64df6dff07870c9d531ae72a47403063238da1a1fe3f9d6a179fa50f96cd4aff9261aa92c0e6f17ec940639bc2ccd0B519A16DF59C53E0D49B209200F878F362ACE518D5B8BFCF9CDC725E5E01C06295E8605AF06932B5006D9E556D3F190E8136BF9C643D332":"0ece49e2f747b4bc43afbacb8fe99e8b7301401d8a9108093fee65a9f4ae65e920a63ac1f2b64df6dff07870c9d531ae72a47403063238db"