diff --git a/script/sql/create/21.times.sql b/script/sql/create/21.times.sql
index ae150f9..0259dc1 100644
--- a/script/sql/create/21.times.sql
+++ b/script/sql/create/21.times.sql
@@ -2,7 +2,7 @@
 
 create table times
 (
-  key   text not null
+  key   text primary key
 , value text not null
 );