diff --git a/src/lib/config/interfaces.ts b/src/lib/config/interfaces.ts
index 5a9308676..8fa6023f9 100644
--- a/src/lib/config/interfaces.ts
+++ b/src/lib/config/interfaces.ts
@@ -36,7 +36,7 @@ export interface Config {
   forbiddenNoteIDs: string[];
   defaultPermission: string;
   dbURL: string;
-  db: any;
+  db;
   sslKeyPath: string;
   sslCertPath: string;
   sslCAPath: string[];
@@ -153,5 +153,6 @@ export interface Config {
   linkifyHeaderStyle: string;
 
   // TODO: Remove escape hatch for dynamically added properties
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   [propName: string]: any;
 }
diff --git a/src/lib/history.ts b/src/lib/history.ts
index 898b96a0f..694900a78 100644
--- a/src/lib/history.ts
+++ b/src/lib/history.ts
@@ -6,6 +6,7 @@ import LZString from 'lz-string'
 import { logger } from './logger'
 import { Note, User } from './models'
 import { errors } from './errors'
+import { LogEntry } from 'winston'
 
 // public
 
@@ -34,7 +35,7 @@ function parseHistoryArrayToMap (historyArray: HistoryObject[]): Map<string, His
   return historyMap
 }
 
-function getHistory (userId, callback: (err: any, history: any) => void): void {
+function getHistory (userId, callback: (err: unknown, history: Map<string, HistoryObject> | null) => void): void {
   User.findOne({
     where: {
       id: userId
@@ -44,7 +45,7 @@ function getHistory (userId, callback: (err: any, history: any) => void): void {
       return callback(null, null)
     }
     if (user.history) {
-      const history = JSON.parse(user.history)
+      const history: HistoryObject[] = JSON.parse(user.history)
       // migrate LZString encoded note id to base64url encoded note id
       for (let i = 0, l = history.length; i < l; i++) {
         // Calculate minimal string length for an UUID that is encoded
@@ -74,14 +75,14 @@ function getHistory (userId, callback: (err: any, history: any) => void): void {
       return callback(null, parseHistoryArrayToMap(history))
     }
     logger.debug(`read empty history: ${user.id}`)
-    return callback(null, [])
+    return callback(null, new Map<string, HistoryObject>())
   }).catch(function (err) {
     logger.error('read history failed: ' + err)
     return callback(err, null)
   })
 }
 
-function setHistory (userId: string, history: any[], callback: (err: any | null, count: [number, User[]] | null) => void): void {
+function setHistory (userId: string, history: HistoryObject[], callback: (err: LogEntry | null, count: [number, User[]] | null) => void): void {
   User.update({
     history: JSON.stringify(history)
   }, {
@@ -109,7 +110,7 @@ function updateHistory (userId: string, noteId: string, document, time): void {
       noteHistory.text = noteInfo.title
       noteHistory.time = time || Date.now()
       noteHistory.tags = noteInfo.tags
-      setHistory(userId, history, function (err, _) {
+      setHistory(userId, parseHistoryMapToArray(history), function (err, _) {
         if (err) {
           logger.log(err)
         }
@@ -118,7 +119,7 @@ function updateHistory (userId: string, noteId: string, document, time): void {
   }
 }
 
-function historyGet (req, res): any {
+function historyGet (req, res): void {
   if (req.isAuthenticated()) {
     getHistory(req.user.id, function (err, history) {
       if (err) return errors.errorInternalError(res)
@@ -132,7 +133,7 @@ function historyGet (req, res): any {
   }
 }
 
-function historyPost (req, res): any {
+function historyPost (req, res): void {
   if (req.isAuthenticated()) {
     const noteId = req.params.noteId
     if (!noteId) {
@@ -160,7 +161,7 @@ function historyPost (req, res): any {
         if (!history[noteId]) return errors.errorNotFound(res)
         if (req.body.pinned === 'true' || req.body.pinned === 'false') {
           history[noteId].pinned = (req.body.pinned === 'true')
-          setHistory(req.user.id, history, function (err, _) {
+          setHistory(req.user.id, parseHistoryMapToArray(history), function (err, _) {
             if (err) return errors.errorInternalError(res)
             res.end()
           })
@@ -174,7 +175,7 @@ function historyPost (req, res): any {
   }
 }
 
-function historyDelete (req, res): any {
+function historyDelete (req, res): void {
   if (req.isAuthenticated()) {
     const noteId = req.params.noteId
     if (!noteId) {
@@ -187,7 +188,7 @@ function historyDelete (req, res): any {
         if (err) return errors.errorInternalError(res)
         if (!history) return errors.errorNotFound(res)
         delete history[noteId]
-        setHistory(req.user.id, history, function (err, _) {
+        setHistory(req.user.id, parseHistoryMapToArray(history), function (err, _) {
           if (err) return errors.errorInternalError(res)
           res.end()
         })
diff --git a/src/lib/library-ext.d.ts b/src/lib/library-ext.d.ts
index fd2ec2d7a..e06789e84 100644
--- a/src/lib/library-ext.d.ts
+++ b/src/lib/library-ext.d.ts
@@ -3,6 +3,6 @@ import { User } from './models'
 declare module 'express' {
   export interface Request {
     user?: User;
-    flash (type: string, msg?: string): any;
+    flash (type: string, msg?: string): [] | object | number;
   }
 }