oid_x520_attr_type list is defined only when MBEDTLS_X509_USE_C or MBEDTLS_X509_CREATE_C
diff --git a/library/oid.c b/library/oid.c
index 763bc6a..bdb9649 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -152,6 +152,7 @@
     return( MBEDTLS_ERR_OID_NOT_FOUND );                                   \
 }
 
+#if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
 /*
  * For X520 attribute types
  */
@@ -247,7 +248,6 @@
 FN_OID_TYPED_FROM_ASN1(oid_x520_attr_t, x520_attr, oid_x520_attr_type)
 FN_OID_GET_ATTR1(mbedtls_oid_get_attr_short_name, oid_x520_attr_t, x520_attr, const char *, short_name)
 
-#if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
 /*
  * For X509 extensions
  */