diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 07f3151214..f0c3d5adfc 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -5735,7 +5735,6 @@ psa_status_t psa_key_derivation_input_key(
 /****************************************************************/
 /* Key agreement */
 /****************************************************************/
-#define PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE MBEDTLS_ECP_MAX_BYTES
 
 psa_status_t psa_key_agreement_raw_builtin( const psa_key_attributes_t *attributes,
                                             const uint8_t *key_buffer,
@@ -5809,7 +5808,7 @@ static psa_status_t psa_key_agreement_internal( psa_key_derivation_operation_t *
                                                 size_t peer_key_length )
 {
     psa_status_t status;
-    uint8_t shared_secret[PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE];
+    uint8_t shared_secret[PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE];
     size_t shared_secret_length = 0;
     psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE( operation->alg );