diff --git a/src/utils/relation.ts b/src/utils/relation.ts
index e5acb4d..9e4ed45 100644
--- a/src/utils/relation.ts
+++ b/src/utils/relation.ts
@@ -10,7 +10,7 @@ function closeRelationServer() {
   }
 }
 
-async function getRelationServer() {
+async function getRelationServer(): Promise<MessageHelper<typeof handlers>> {
   if (!addon.data.relation.server) {
     const worker = new Worker(
       `chrome://${config.addonRef}/content/scripts/relationWorker.js`,
@@ -95,7 +95,9 @@ async function updateNoteLinkRelation(noteID: number) {
   );
 }
 
-async function getNoteLinkOutboundRelation(noteID: number) {
+async function getNoteLinkOutboundRelation(
+  noteID: number,
+): Promise<LinkModel[]> {
   const note = Zotero.Items.get(noteID);
   const fromLibID = note.libraryID;
   const fromKey = note.key;
@@ -104,7 +106,9 @@ async function getNoteLinkOutboundRelation(noteID: number) {
   ).proxy.getOutboundLinks(fromLibID, fromKey);
 }
 
-async function getNoteLinkInboundRelation(noteID: number) {
+async function getNoteLinkInboundRelation(
+  noteID: number,
+): Promise<LinkModel[]> {
   const note = Zotero.Items.get(noteID);
   const toLibID = note.libraryID;
   const toKey = note.key;
@@ -135,13 +139,19 @@ async function linkAnnotationToTarget(model: AnnotationModel) {
   return await (await getRelationServer()).proxy.linkAnnotationToTarget(model);
 }
 
-async function getLinkTargetByAnnotation(fromLibID: number, fromKey: string) {
+async function getLinkTargetByAnnotation(
+  fromLibID: number,
+  fromKey: string,
+): Promise<AnnotationModel | undefined> {
   return await (
     await getRelationServer()
   ).proxy.getLinkTargetByAnnotation(fromLibID, fromKey);
 }
 
-async function getAnnotationByLinkTarget(toLibID: number, toKey: string) {
+async function getAnnotationByLinkTarget(
+  toLibID: number,
+  toKey: string,
+): Promise<AnnotationModel | undefined> {
   return await (
     await getRelationServer()
   ).proxy.getAnnotationByLinkTarget(toLibID, toKey);
diff --git a/test/tsconfig.json b/test/tsconfig.json
index edf7509..172b640 100644
--- a/test/tsconfig.json
+++ b/test/tsconfig.json
@@ -1,8 +1,5 @@
 {
   "extends": "../tsconfig.json",
-  "compilerOptions": {
-    "composite": true
-  },
   "include": ["./**/*.spec.ts", "typings", "../node_modules/zotero-types"],
   "exclude": []
 }
diff --git a/tsconfig.json b/tsconfig.json
index f7f5bfb..7c19530 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -8,11 +8,7 @@
     "skipLibCheck": true,
     "alwaysStrict": false,
     "strict": true,
-    "composite": true
   },
   "include": ["src", "typings", "node_modules/zotero-types"],
   "exclude": ["build", "addon", "test"],
-  "references": [
-    { "path": "./test" }
-  ]
 }