diff --git a/package.json b/package.json
index 77333e7..8497abd 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
     "danger-plugin",
     "learning mentor trivia"
   ],
-  "version": "0.0.0-development",
+  "version": "0.1.0",
   "main": "dist/index.js",
   "types": "types/index.d.ts",
   "scripts": {
diff --git a/src/index.ts b/src/index.ts
index ec01f28..93baf6f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -11,5 +11,5 @@ export declare function markdown(message: string): void
  * Level up your programming skills by getting bite-sized tips and tricks in your pull requests.
  */
 export default function mentor() {
-  message(RandomTip().text)
+  message(RandomTip().toMarkdown())
 }
diff --git a/src/tip.test.ts b/src/tip.test.ts
new file mode 100644
index 0000000..ed1728f
--- /dev/null
+++ b/src/tip.test.ts
@@ -0,0 +1,15 @@
+import Tip from "./tip"
+
+describe("Tip", () => {
+  describe("#toMarkdown", () => {
+    it("concats the text and the source", () => {
+      expect(new Tip("A tip with a source.", new URL("http://example.com")).toMarkdown()).toEqual(
+        "A tip with a source. Source: [http://example.com/](http://example.com/)"
+      )
+    })
+
+    it("leaves out the source if not present", () => {
+      expect(new Tip("A tip with a source.").toMarkdown()).toEqual("A tip with a source.")
+    })
+  })
+})
diff --git a/src/tip.ts b/src/tip.ts
index 39fd155..0d3561b 100644
--- a/src/tip.ts
+++ b/src/tip.ts
@@ -1,7 +1,17 @@
 export default class Tip {
-  text: string
+  private text: string
+  private source?: URL
 
-  constructor(text: string) {
+  constructor(text: string, source?: URL) {
     this.text = text
+    this.source = source
+  }
+
+  toMarkdown(): string {
+    if (this.source) {
+      return `${this.text} Source: [${this.source}](${this.source})`
+    }
+
+    return this.text
   }
 }