diff --git a/db.sh b/db.sh
index 82d89d19f..8861a2ac4 100755
--- a/db.sh
+++ b/db.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Options: see /test/Database.hs (Main)
 stack build --fast --flag uniworx:library-only --flag uniworx:dev
 stack exec uniworxdb -- $@
diff --git a/src/Model/Migration.hs b/src/Model/Migration.hs
index ac11d3241..38de10773 100644
--- a/src/Model/Migration.hs
+++ b/src/Model/Migration.hs
@@ -207,6 +207,15 @@ customMigrations = Map.fromListWith (>>)
            UPDATE "sheet" SET "type" = json_build_object('type', "type"->'type', 'grading', json_build_object('type', "type"->'grading'->'type', 'max', "type"->'grading'->'points', 'passing', 0)) WHERE ("type"->'grading'->'type') = '"pass-points"' AND jsonb_exists("type"->'grading', 'points');
         |]
     )
+  , ( AppliedMigrationKey [migrationVersion|8.0.0|] [version|9.0.0|]
+    , whenM ((\a b c -> a && b && not c) <$> tableExists "study_features" <*> tableExists "course_participant" <*> columnExists "course_participant" "field") $ do
+        [executeQQ|
+          ALTER TABLE "course_participant" ADD COLUMN "field" bigint DEFAULT null REFERENCES study_features(id);
+          ALTER TABLE "study_features" ADD COLUMN IF NOT EXISTS "valid" boolean NOT NULL DEFAULT true;
+        |]
+        users <- [sqlQQ| SELECT DISTINCT ON ("user"."id") "user"."id", "study_features"."id" FROM "user", "study_features" WHERE "study_features"."user" = "user"."id" AND "study_features"."valid" AND "study_features"."type" = 'FieldPrimary' ORDER BY "user"."id", random(); |]
+        forM_ users $ \(uid :: UserId, sfid :: StudyFeaturesId) -> [executeQQ| UPDATE "course_participant" SET "field" = #{sfid} WHERE "user" = #{uid} AND "field" IS NULL; |]
+    )
   ]