diff --git a/backend/.sqlc/migrations/20241219000000_add_token_salt_to_users.sql b/backend/.sqlc/migrations/20241219000000_add_token_salt_to_users.sql
index 6e754d1e..012f7e25 100644
--- a/backend/.sqlc/migrations/20241219000000_add_token_salt_to_users.sql
+++ b/backend/.sqlc/migrations/20241219000000_add_token_salt_to_users.sql
@@ -7,8 +7,9 @@ ALTER TABLE users ADD COLUMN token_salt BYTEA;
 -- backfill existing users with random salt
 UPDATE users SET token_salt = gen_random_bytes(32);
 
--- make token_salt non-nullable
+-- make token_salt non-nullable and unique
 ALTER TABLE users ALTER COLUMN token_salt SET NOT NULL;
+ALTER TABLE users ADD CONSTRAINT users_token_salt_key UNIQUE (token_salt);
 -- +goose StatementEnd
 
 -- +goose Down