diff --git a/Media/icon.png b/Media/icon.png
new file mode 100644
index 0000000..e54d8fb
Binary files /dev/null and b/Media/icon.png differ
diff --git a/src/Tests/Tests.Messages.ts b/src/Tests/Tests.Messages.ts
index 8e09822..4c152de 100644
--- a/src/Tests/Tests.Messages.ts
+++ b/src/Tests/Tests.Messages.ts
@@ -71,7 +71,13 @@ WAConnectionTest('Messages', conn => {
     it('should send an image', async () => {
         const content = await fs.readFile('./Media/meme.jpeg')
         const message = await sendAndRetreiveMessage(conn, content, MessageType.image)
-        
+        assert.ok (message.message?.imageMessage?.jpegThumbnail)
+        await conn.downloadMediaMessage(message)
+    })
+    it('should send a png image', async () => {
+        const content = await fs.readFile('./Media/icon.png')
+        const message = await sendAndRetreiveMessage(conn, content, MessageType.image, { mimetype: 'image/png' })
+        assert.ok (message.message?.imageMessage?.jpegThumbnail)
         await conn.downloadMediaMessage(message)
     })
     it('should send a sticker', async () => {
diff --git a/src/WAConnection/6.MessagesSend.ts b/src/WAConnection/6.MessagesSend.ts
index 773e900..449e869 100644
--- a/src/WAConnection/6.MessagesSend.ts
+++ b/src/WAConnection/6.MessagesSend.ts
@@ -73,7 +73,11 @@ export class WAConnection extends Base {
             case MessageType.contact:
                 m.contactMessage = WAMessageProto.ContactMessage.create(message as any)
                 break
-            default:
+            case MessageType.image:
+            case MessageType.sticker:
+            case MessageType.document:
+            case MessageType.video:
+            case MessageType.audio:
                 m = await this.prepareMessageMedia(message as Buffer, type, options)
                 break
         }
diff --git a/src/WAConnection/Utils.ts b/src/WAConnection/Utils.ts
index 983c1d4..96391b8 100644
--- a/src/WAConnection/Utils.ts
+++ b/src/WAConnection/Utils.ts
@@ -238,7 +238,7 @@ export const mediaMessageSHA256B64 = (message: WAMessageContent) => {
 
 /** generates a thumbnail for a given media, if required */
 export async function generateThumbnail(buffer: Buffer, mediaType: MessageType, info: MessageOptions) {
-    if (info.thumbnail === null || info.thumbnail) {
+    if ('thumbnail' in info) {
         // don't do anything if the thumbnail is already provided, or is null
         if (mediaType === MessageType.audio) {
             throw new Error('audio messages cannot have thumbnails')
diff --git a/yarn.lock b/yarn.lock
index 7a5be11..eebfa0f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -393,9 +393,9 @@
   integrity sha512-7NQmHra/JILCd1QqpSzl8+mJRc8ZHz3uDm8YV1Ks9IhK0epEiTw8aIErbvH9PI+6XbqhyIQy3462nEsn7UVzjQ==
 
 "@types/ws@^7.2.6":
-  version "7.2.6"
-  resolved "https://registry.yarnpkg.com/@types/ws/-/ws-7.2.6.tgz#516cbfb818310f87b43940460e065eb912a4178d"
-  integrity sha512-Q07IrQUSNpr+cXU4E4LtkSIBPie5GLZyyMC1QtQYRLWz701+XcoVygGUZgvLqElq1nU4ICldMYPnexlBsg3dqQ==
+  version "7.2.7"
+  resolved "https://registry.yarnpkg.com/@types/ws/-/ws-7.2.7.tgz#362ad1a1d62721bdb725e72c8cccf357078cf5a3"
+  integrity sha512-UUFC/xxqFLP17hTva8/lVT0SybLUrfSD9c+iapKb0fEiC8uoDbA+xuZ3pAN603eW+bY8ebSMLm9jXdIPnD0ZgA==
   dependencies:
     "@types/node" "*"
 
@@ -1288,9 +1288,9 @@ map-obj@^1.0.0, map-obj@^1.0.1:
   integrity sha1-2TPOuSBdgr3PSIb2dCvcK03qFG0=
 
 marked@^1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/marked/-/marked-1.1.1.tgz#e5d61b69842210d5df57b05856e0c91572703e6a"
-  integrity sha512-mJzT8D2yPxoPh7h0UXkB+dBj4FykPJ2OIfxAWeIHrvoHDkFxukV/29QxoFQoPM6RLEwhIFdJpmKBlqVM3s2ZIw==
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/marked/-/marked-1.2.0.tgz#7221ce2395fa6cf6d722e6f2871a32d3513c85ca"
+  integrity sha512-tiRxakgbNPBr301ihe/785NntvYyhxlqcL3YaC8CaxJQh7kiaEtrN9B/eK2I2943Yjkh5gw25chYFDQhOMCwMA==
 
 meow@^3.3.0:
   version "3.7.0"