diff --git a/src/FileUploadMiddleware.ts b/src/FileUploadMiddleware.ts
index 7aa353e..e6159cf 100644
--- a/src/FileUploadMiddleware.ts
+++ b/src/FileUploadMiddleware.ts
@@ -23,9 +23,9 @@ export default abstract class FileUploadMiddleware extends Middleware {
                     resolve();
                 });
             });
-        } catch (e: any) {
+        } catch (e) {
             const bag = new ValidationBag();
-            const fileError = new FileError(e);
+            const fileError = new FileError(String(e));
             fileError.thingName = this.getDefaultField();
             bag.addMessage(fileError);
             next(bag);
diff --git a/src/Utils.ts b/src/Utils.ts
index b4920a7..443319b 100644
--- a/src/Utils.ts
+++ b/src/Utils.ts
@@ -1,4 +1,4 @@
-import {promises as fs} from "fs";
+import fs, {promises as afs} from "fs";
 import path from "path";
 
 export async function sleep(ms: number): Promise<void> {
@@ -49,10 +49,10 @@ export function getMethods<T extends { [p: string]: unknown }>(obj: T): string[]
 }
 
 export async function listFilesRecursively(dir: string): Promise<string[]> {
-    const localFiles = await fs.readdir(dir);
+    const localFiles = await afs.readdir(dir);
     const files: string[] = [];
     for (const file of localFiles.map(file => path.join(dir, file))) {
-        const stat = await fs.stat(file);
+        const stat = await afs.stat(file);
 
         if (stat.isDirectory()) {
             files.push(...await listFilesRecursively(file));
@@ -65,14 +65,17 @@ export async function listFilesRecursively(dir: string): Promise<string[]> {
 
 
 export async function doesFileExist(file: string): Promise<boolean> {
-    try {
-        await fs.stat(file);
-    } catch (err: any) {
-        if (err?.code === 'ENOENT') {
-            return false;
-        } else {
-            throw err;
-        }
-    }
-    return true;
+    return await new Promise<boolean>((resolve, reject) => {
+        fs.stat(file, err => {
+            if (err) {
+                if (err.code === 'ENOENT') {
+                    return resolve(false);
+                } else {
+                    return reject(err);
+                }
+            } else {
+                return resolve(true);
+            }
+        });
+    });
 }
diff --git a/src/components/MailComponent.ts b/src/components/MailComponent.ts
index 391924d..4109c06 100644
--- a/src/components/MailComponent.ts
+++ b/src/components/MailComponent.ts
@@ -48,8 +48,12 @@ export default class MailComponent extends ApplicationComponent {
             try {
                 await util.promisify(transporter.verify)();
                 this.transporter = transporter;
-            } catch (e: any) {
-                throw new MailError('Connection to mail service unsuccessful.', e);
+            } catch (e) {
+                if (e instanceof Error) {
+                    throw new MailError('Connection to mail service unsuccessful.', e);
+                } else {
+                    throw e;
+                }
             }
 
             logger.info(`Mail ready to be distributed via ${config.get('mail.host')}:${config.get('mail.port')}`);
diff --git a/src/db/MysqlConnectionManager.ts b/src/db/MysqlConnectionManager.ts
index 5183493..e5ee183 100644
--- a/src/db/MysqlConnectionManager.ts
+++ b/src/db/MysqlConnectionManager.ts
@@ -183,9 +183,14 @@ export default class MysqlConnectionManager {
         try {
             const result = await query('SELECT id FROM migrations ORDER BY id DESC LIMIT 1');
             currentVersion = Number(result.results[0]?.id);
-        } catch (e: any) {
-            if (e.code === 'ECONNREFUSED' || e.code !== 'ER_NO_SUCH_TABLE') {
-                throw new Error('Cannot run migrations: ' + e.code);
+        } catch (e) {
+            if (e instanceof Error) {
+                const mysqlError = e as MysqlError;
+                if (mysqlError.code !== 'ER_NO_SUCH_TABLE') {
+                    throw new Error('Cannot run migrations: ' + mysqlError.code);
+                }
+            } else {
+                throw e;
             }
         }
 
diff --git a/src/db/Validator.ts b/src/db/Validator.ts
index 18ea2b8..2a1136e 100644
--- a/src/db/Validator.ts
+++ b/src/db/Validator.ts
@@ -61,8 +61,12 @@ export default class Validator<V> {
                 if (result instanceof Promise) {
                     result = await result;
                 }
-            } catch (e: any) {
-                throw new ServerError(`An error occurred while validating ${thingName} with value "${value}".`, e);
+            } catch (e) {
+                if (e instanceof Error) {
+                    throw new ServerError(`An error occurred while validating ${thingName} with value "${value}".`, e);
+                } else {
+                    throw e;
+                }
             }
 
             if (result === false && step.throw) {
diff --git a/src/migrations/CreateMigrationsTable.ts b/src/migrations/CreateMigrationsTable.ts
index 21dadc3..22be569 100644
--- a/src/migrations/CreateMigrationsTable.ts
+++ b/src/migrations/CreateMigrationsTable.ts
@@ -1,3 +1,5 @@
+import {MysqlError} from "mysql";
+
 import Migration from "../db/Migration.js";
 import {query} from "../db/MysqlConnectionManager.js";
 
@@ -8,8 +10,8 @@ export default class CreateMigrationsTable extends Migration {
     public async shouldRun(currentVersion: number): Promise<boolean> {
         try {
             await query('SELECT 1 FROM migrations LIMIT 1');
-        } catch (e: any) {
-            if (e.code !== 'ER_NO_SUCH_TABLE') {
+        } catch (e) {
+            if (!(e instanceof Error) || (e as MysqlError).code !== 'ER_NO_SUCH_TABLE') {
                 return false;
             }
         }