diff --git a/entc/integration/customid/ent/migrate/schema.go b/entc/integration/customid/ent/migrate/schema.go
index 3be7232cf..6678aa349 100644
--- a/entc/integration/customid/ent/migrate/schema.go
+++ b/entc/integration/customid/ent/migrate/schema.go
@@ -14,7 +14,7 @@ import (
 var (
 	// BlobsColumns holds the columns for the "blobs" table.
 	BlobsColumns = []*schema.Column{
-		{Name: "id", Type: field.TypeUUID},
+		{Name: "id", Type: field.TypeUUID, Unique: true},
 		{Name: "uuid", Type: field.TypeUUID, Unique: true},
 		{Name: "blob_parent", Type: field.TypeUUID, Unique: true, Nullable: true},
 	}
diff --git a/entc/integration/customid/ent/schema/blob.go b/entc/integration/customid/ent/schema/blob.go
index 2938d388d..90abb36a2 100644
--- a/entc/integration/customid/ent/schema/blob.go
+++ b/entc/integration/customid/ent/schema/blob.go
@@ -21,7 +21,8 @@ type Blob struct {
 func (Blob) Fields() []ent.Field {
 	return []ent.Field{
 		field.UUID("id", uuid.UUID{}).
-			Default(uuid.New),
+			Default(uuid.New).
+			Unique(),
 		field.UUID("uuid", uuid.UUID{}).
 			Default(uuid.New).
 			Unique(),