diff --git a/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java b/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java
index f9dd759b4..6eda44826 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java
@@ -102,12 +102,10 @@ class AttachmentCreationTask {
 		}
 		InputStream is = contentResolver.openInputStream(uri);
 		if (is == null) throw new IOException();
-		is = imageCompressor
-				.compressImage(is, contentType);
+		is = imageCompressor.compressImage(is, contentType);
 		long timestamp = System.currentTimeMillis();
-		AttachmentHeader h = messagingManager
-				.addLocalAttachment(groupId, timestamp,
-						ImageCompressor.MIME_TYPE, is);
+		AttachmentHeader h = messagingManager.addLocalAttachment(groupId,
+				timestamp, ImageCompressor.MIME_TYPE, is);
 		tryToClose(is, LOG, WARNING);
 		logDuration(LOG, "Storing attachment", start);
 		return h;
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressor.java b/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressor.java
index 2c2d150c7..3919ba36d 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressor.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressor.java
@@ -11,7 +11,7 @@ public interface ImageCompressor {
 	/**
 	 * The MIME type of compressed images
 	 */
-	String MIME_TYPE = "image/jpeg";
+	String MIME_TYPE = "image/webp";
 
 	/**
 	 * Load an image from {@code is}, compress it and return an InputStream
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressorImpl.java b/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressorImpl.java
index e990fbb93..7cd5661d2 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressorImpl.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/attachment/media/ImageCompressorImpl.java
@@ -12,7 +12,7 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
-import static android.graphics.Bitmap.CompressFormat.JPEG;
+import static android.graphics.Bitmap.CompressFormat.WEBP;
 import static android.graphics.BitmapFactory.decodeStream;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
@@ -50,7 +50,7 @@ class ImageCompressorImpl implements ImageCompressor {
 	public InputStream compressImage(Bitmap bitmap) throws IOException {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		for (int quality = 100; quality >= 0; quality -= 10) {
-			if (!bitmap.compress(JPEG, quality, out))
+			if (!bitmap.compress(WEBP, quality, out))
 				throw new IOException();
 			if (out.size() <= MAX_IMAGE_SIZE) {
 				if (LOG.isLoggable(INFO)) {
diff --git a/briar-api/src/main/java/org/briarproject/briar/api/test/TestAvatarCreator.java b/briar-api/src/main/java/org/briarproject/briar/api/test/TestAvatarCreator.java
index d2d322c92..ee6ebe430 100644
--- a/briar-api/src/main/java/org/briarproject/briar/api/test/TestAvatarCreator.java
+++ b/briar-api/src/main/java/org/briarproject/briar/api/test/TestAvatarCreator.java
@@ -6,6 +6,9 @@ import java.io.InputStream;
 import javax.annotation.Nullable;
 
 public interface TestAvatarCreator {
+
+	String MIME_TYPE = "image/webp";
+
 	@Nullable
 	InputStream getAvatarInputStream() throws IOException;
 }
diff --git a/briar-core/src/main/java/org/briarproject/briar/test/TestDataCreatorImpl.java b/briar-core/src/main/java/org/briarproject/briar/test/TestDataCreatorImpl.java
index fa401edb4..e74fdb8d3 100644
--- a/briar-core/src/main/java/org/briarproject/briar/test/TestDataCreatorImpl.java
+++ b/briar-core/src/main/java/org/briarproject/briar/test/TestDataCreatorImpl.java
@@ -316,7 +316,7 @@ public class TestDataCreatorImpl implements TestDataCreator {
 		Message m;
 		try {
 			m = avatarMessageEncoder.encodeUpdateMessage(groupId, 0,
-					"image/jpeg", is).getFirst();
+					TestAvatarCreator.MIME_TYPE, is).getFirst();
 		} catch (IOException e) {
 			throw new DbException(e);
 		}