diff --git a/library/psa_crypto_ffdh.c b/library/psa_crypto_ffdh.c
index 813c1380cf..ef77068170 100644
--- a/library/psa_crypto_ffdh.c
+++ b/library/psa_crypto_ffdh.c
@@ -269,8 +269,11 @@ psa_status_t mbedtls_psa_ffdh_key_agreement(
     mbedtls_mpi P, X, GY, K;
     const size_t calculated_shared_secret_size = key_buffer_size;
 
-    if (peer_key_length != key_buffer_size ||
-        !PSA_KEY_TYPE_IS_DH_KEY_PAIR(psa_get_key_type(attributes))) {
+    if (!PSA_KEY_TYPE_IS_DH_KEY_PAIR(psa_get_key_type(attributes))) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (peer_key_length != key_buffer_size) {
         return PSA_ERROR_INVALID_ARGUMENT;
     }