diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 7830f40f46..4fc940c9f4 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1714,7 +1714,7 @@ psa_status_t psa_export_public_key_internal(
 }
 
 psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key,
-                                   uint8_t *data,
+                                   uint8_t *data_external,
                                    size_t data_size,
                                    size_t *data_length)
 {
@@ -1722,6 +1722,7 @@ psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key,
     psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
     psa_key_slot_t *slot;
     psa_key_attributes_t attributes;
+    LOCAL_OUTPUT_DECLARE(data_external, data);
 
     /* Reject a zero-length output buffer now, since this can never be a
      * valid key representation. This way we know that data must be a valid
@@ -1742,6 +1743,8 @@ psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key,
         return status;
     }
 
+    LOCAL_OUTPUT_ALLOC(data_external, data_size, data);
+
     if (!PSA_KEY_TYPE_IS_ASYMMETRIC(slot->attr.type)) {
         status = PSA_ERROR_INVALID_ARGUMENT;
         goto exit;
@@ -1757,6 +1760,7 @@ psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key,
 exit:
     unlock_status = psa_unlock_key_slot(slot);
 
+    LOCAL_OUTPUT_FREE(data_external, data);
     return (status == PSA_SUCCESS) ? unlock_status : status;
 }