diff --git a/keyserver/src/database/migration-config.js b/keyserver/src/database/migration-config.js
--- a/keyserver/src/database/migration-config.js
+++ b/keyserver/src/database/migration-config.js
@@ -147,6 +147,25 @@
       `);
     },
   ],
+  [
+    15,
+    async () => {
+      await dbQuery(
+        SQL`
+          ALTER TABLE uploads 
+            ADD COLUMN IF NOT EXISTS thread bigint(20) DEFAULT NULL,
+            ADD INDEX IF NOT EXISTS thread (thread);
+          
+          UPDATE uploads 
+            SET thread = (
+              SELECT thread FROM messages 
+              WHERE messages.id = uploads.container
+            );
+        `,
+        { multipleStatements: true },
+      );
+    },
+  ],
 ]);
 const newDatabaseVersion: number = Math.max(...migrations.keys());
 
diff --git a/keyserver/src/database/setup-db.js b/keyserver/src/database/setup-db.js
--- a/keyserver/src/database/setup-db.js
+++ b/keyserver/src/database/setup-db.js
@@ -170,6 +170,7 @@
 
       CREATE TABLE uploads (
         id bigint(20) NOT NULL,
+        thread bigint(20) DEFAULT NULL,
         uploader bigint(20) NOT NULL,
         container bigint(20) DEFAULT NULL,
         type varchar(255) NOT NULL,
@@ -320,7 +321,8 @@
 
       ALTER TABLE uploads
         ADD PRIMARY KEY (id),
-        ADD INDEX container (container);
+        ADD INDEX container (container),
+        ADD INDEX thread (thread);
 
       ALTER TABLE users
         ADD PRIMARY KEY (id),