diff --git a/libs/event-emitter/src/redmine-data-loader/redmine-data-loader.ts b/libs/event-emitter/src/redmine-data-loader/redmine-data-loader.ts
index 6df42ee..861baa6 100644
--- a/libs/event-emitter/src/redmine-data-loader/redmine-data-loader.ts
+++ b/libs/event-emitter/src/redmine-data-loader/redmine-data-loader.ts
@@ -1,28 +1,35 @@
 import axios from 'axios';
 import { RedmineIssueData } from '../models/RedmineIssueData';
-import { Injectable } from '@nestjs/common';
+import { Injectable, Logger } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
 
 @Injectable()
 export class RedmineDataLoader {
   urlPrefix: string;
 
+  private logger = new Logger(RedmineDataLoader.name);
+
   constructor(private configService: ConfigService) {
     this.urlPrefix = this.configService.get<string>('redmineUrlPrefix');
   }
 
-  async loadIssues(issues: number[]): Promise<RedmineIssueData[]> {
+  async loadIssues(issues: number[]): Promise<(RedmineIssueData | null)[]> {
     const promises = issues.map((issue) => this.loadIssue(issue));
     return Promise.all(promises);
   }
 
-  async loadIssue(issueNumber: number): Promise<RedmineIssueData> {
+  async loadIssue(issueNumber: number): Promise<RedmineIssueData | null> {
     const url = this.getUrl(issueNumber);
     const resp = await axios.get(url);
     if (!resp || !resp.data || !resp.data.issue) {
-      console.error('Failed to load data from redmine');
+      this.logger.error(
+        `Failed to load data for from redmine, issueNumber = ${issueNumber}`,
+      );
       return null;
     }
+    this.logger.debug(
+      `Loaded issue, issueNumber = ${issueNumber}, subject = ${resp.data.issue.subject}`,
+    );
     return resp.data.issue;
   }