diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 1112cfcd59..7b6f5ae04d 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -9500,7 +9500,9 @@ void ecc_conversion_functions_fail()
 {
     size_t bits;
 
-    /* Invalid legacy curve identifier. */
+    /* Invalid legacy curve identifiers. */
+    TEST_EQUAL(0, mbedtls_ecc_group_to_psa(MBEDTLS_ECP_DP_MAX, &bits));
+    TEST_EQUAL(0, bits);
     TEST_EQUAL(0, mbedtls_ecc_group_to_psa(MBEDTLS_ECP_DP_NONE, &bits));
     TEST_EQUAL(0, bits);