diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 16f5f8cd7..819d5279f 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1324,8 +1324,8 @@ void ecp_mod_p_generic_raw(int curve_id,
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) && defined(MBEDTLS_ECP_NIST_OPTIM)
         case MBEDTLS_ECP_DP_SECP521R1:
-            limbs = BITS_TO_LIMBS(522) * 2;
-            curve_bits = 522;
+            limbs = BITS_TO_LIMBS(521) * 2;
+            curve_bits = 521;
             curve_func = &mbedtls_ecp_mod_p521_raw;
             break;
 #endif