diff --git a/src/fsrs/default.ts b/src/fsrs/default.ts
index d737236..c341da7 100644
--- a/src/fsrs/default.ts
+++ b/src/fsrs/default.ts
@@ -32,7 +32,7 @@ export const default_enable_fuzz = envParams.FSRS_ENABLE_FUZZ || false;
 
 export const FSRSVersion: string = "3.0.4";
 
-export const generatorParameters = (props?: Partial<FSRSParameters>) => {
+export const generatorParameters = (props?: Partial<FSRSParameters>): FSRSParameters => {
   return {
     request_retention: props?.request_retention || default_request_retention,
     maximum_interval: props?.maximum_interval || default_maximum_interval,
@@ -54,6 +54,6 @@ export const createEmptyCard = (now?: Date): Card => {
   };
 };
 
-export const fsrs = (params?: Partial<FSRSParameters>) => {
+export const fsrs = (params?: Partial<FSRSParameters>): FSRS => {
   return new FSRS(params || {});
 };
diff --git a/src/fsrs/fsrs.ts b/src/fsrs/fsrs.ts
index 5391665..46fbb23 100644
--- a/src/fsrs/fsrs.ts
+++ b/src/fsrs/fsrs.ts
@@ -1,6 +1,6 @@
 import { SchedulingCard } from "./index";
 import { fixDate, fixState } from "./help";
-import { FSRSParameters, Card, State, CardInput, DateInput } from "./models";
+import { FSRSParameters, Card, State, CardInput, DateInput, RecordLog } from "./models";
 import type { int } from "./type";
 import { FSRSAlgorithm } from "./algorithm";
 
@@ -20,7 +20,7 @@ export class FSRS extends FSRSAlgorithm {
     return { card, now };
   }
 
-  repeat = (card: CardInput, now: DateInput) => {
+  repeat = (card: CardInput, now: DateInput): RecordLog => {
     const process = this.preProcess(card, now);
     card = process.card;
     now = process.now;
diff --git a/src/fsrs/index.ts b/src/fsrs/index.ts
index 56d19df..b329752 100644
--- a/src/fsrs/index.ts
+++ b/src/fsrs/index.ts
@@ -22,6 +22,8 @@ export type {
   FSRSParameters,
   Card,
   ReviewLog,
+  RecordLog,
+  RecordLogItem,
   StateType,
   RatingType,
   CardInput,