diff --git a/migrations/00005_schema_asset_contract.sql b/migrations/00005_schema_asset_contract.sql
index 5db5950..9fc7ec0 100644
--- a/migrations/00005_schema_asset_contract.sql
+++ b/migrations/00005_schema_asset_contract.sql
@@ -3,7 +3,7 @@
 -------------------------------------------------------------------------
 -- ALTER ASSET  ---------------------------------------------------------
 ALTER TABLE asset 
-    ADD COLUMN address TEXT DEFAULT '' NOT NULL;
+    ADD COLUMN address TEXT DEFAULT '';
 
 -------------------------------------------------------------------------
 -- ALTER CONTRACT TABLE -------------------------------------------------