diff --git a/README.md b/README.md
index 838a9e2..ec6027b 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,7 @@ CREATE TABLE users (
 
 CREATE TABLE progresses (
   id BIGSERIAL PRIMARY KEY,
-  user_id BIGINT,
+  user_id BIGINT NOT NULL,
   document TEXT NOT NULL,
   progress TEXT NOT NULL,
   percentage REAL NOT NULL,