diff --git a/bin/migrations/builder_migrations.ml b/bin/migrations/builder_migrations.ml
index b152d44..26e0fa9 100644
--- a/bin/migrations/builder_migrations.ml
+++ b/bin/migrations/builder_migrations.ml
@@ -65,6 +65,16 @@ let r20210126 =
   Cmdliner.Term.(const do_database_action $ const M20210126.rollback $ setup_log $ dbpath),
   Cmdliner.Term.info ~doc "rollback-2021-01-26"
 
+let m20210202 =
+  let doc = "Adds an index 'job_build_idx' on 'build' (2021-02-02)" in
+  Cmdliner.Term.(const do_database_action $ const M20210202.migrate $ setup_log $ dbpath),
+  Cmdliner.Term.info ~doc "migrate-2021-02-02"
+
+let r20210202 =
+  let doc = "Rollback index 'job_build_idx' on 'build' (2021-02-02)" in
+  Cmdliner.Term.(const do_database_action $ const M20210202.rollback $ setup_log $ dbpath),
+  Cmdliner.Term.info ~doc "rollback-2021-02-02"
+
 let help_cmd =
   let topic =
     let doc = "Migration to get help on" in
@@ -82,6 +92,8 @@ let default_cmd =
 let () =
   Cmdliner.Term.eval_choice
     default_cmd
-    [help_cmd;
-     m20210126; r20210126]
+    [ help_cmd;
+      m20210126; r20210126;
+      m20210202; r20210202;
+    ]
   |> Cmdliner.Term.exit
diff --git a/bin/migrations/m20210202.ml b/bin/migrations/m20210202.ml
new file mode 100644
index 0000000..43a5914
--- /dev/null
+++ b/bin/migrations/m20210202.ml
@@ -0,0 +1,26 @@
+open Rresult.R.Infix
+
+let migrate (module Db : Caqti_blocking.CONNECTION) =
+  let job_build_idx =
+    Caqti_request.exec ~oneshot:true
+      Caqti_type.unit
+      "CREATE INDEX job_build_idx ON build(job)";
+  in
+  Db.find Builder_db.get_application_id () >>= fun application_id ->
+  Db.find Builder_db.get_version () >>= fun user_version ->
+  if application_id <> Builder_db.application_id || user_version <> 1L
+  then Error (`Wrong_version (application_id, user_version))
+  else Db.exec job_build_idx ()
+
+let rollback (module Db : Caqti_blocking.CONNECTION) =
+  let q =
+    Caqti_request.exec ~oneshot:true
+      Caqti_type.unit
+      "DROP INDEX IF EXISTS job_build_idx"
+  in
+  Db.find Builder_db.get_application_id () >>= fun application_id ->
+  Db.find Builder_db.get_version () >>= fun user_version ->
+  if application_id <> Builder_db.application_id || user_version <> 1L
+  then Error (`Wrong_version (application_id, user_version))
+  else
+    Db.exec q ()
diff --git a/db/builder_db.ml b/db/builder_db.ml
index f7063ec..f221f83 100644
--- a/db/builder_db.ml
+++ b/db/builder_db.ml
@@ -474,6 +474,8 @@ let migrate = [
   Build_artifact.migrate;
   Build_file.migrate;
   User.migrate;
+  Caqti_request.exec Caqti_type.unit
+    "CREATE INDEX job_build_idx ON build(job)";
   set_current_version;
   set_application_id;
 ]
@@ -484,6 +486,8 @@ let rollback = [
   Build_artifact.rollback;
   Build.rollback;
   Job.rollback;
+  Caqti_request.exec Caqti_type.unit
+    "DROP INDEX IF EXISTS job_build_idx";
   Caqti_request.exec Caqti_type.unit
     "PRAGMA user_version = 0";
   Caqti_request.exec Caqti_type.unit