diff --git a/src/PdfCreator.ts b/src/PdfCreator.ts
index 8e547b2..2345c8c 100644
--- a/src/PdfCreator.ts
+++ b/src/PdfCreator.ts
@@ -1,6 +1,8 @@
 import fs from "fs";
 import pdf_converter from "html-pdf";
 import path from 'path';
+import { Stream } from 'stream';
+
 /**
  * This class is responsible for all things pdf creation.
  * This uses the html templates from src/templates.
@@ -17,6 +19,10 @@ export class PdfCreator {
 
 }
 
+/**
+ * This class is a wrapper for the pdf objects created by html-pdf.
+ * It offers typed conversion to Buffer and Stream.
+ */
 export class Pdf {
     content: any;
 
@@ -27,9 +33,9 @@ export class Pdf {
     /**
      * Promise wrapper function that resolves the toBuffer promise for pdf generation.
      */
-    public async toBuffer(): Promise<any> {
-        let promise = await new Promise((resolve, reject) => {
-            this.content.toBuffer(function (err, buffer) {
+    public async toBuffer(): Promise<Buffer> {
+        let promise = await new Promise<Buffer>((resolve, reject) => {
+            this.content.toBuffer(function (err, buffer: Buffer) {
                 resolve(buffer);
             });
         });
@@ -39,9 +45,9 @@ export class Pdf {
     /**
      * Promise wrapper function that resolves the toStream promise for pdf generation.
      */
-    public async toStream(): Promise<any> {
-        let promise = await new Promise((resolve, reject) => {
-            this.content.toStream(function (err, stream) {
+    public async toStream(): Promise<Stream> {
+        let promise = await new Promise<Stream>((resolve, reject) => {
+            this.content.toStream(function (err, stream: Stream) {
                 resolve(stream);
             });
         });