diff --git a/lib/src/room.dart b/lib/src/room.dart
index d09581b..3be3291 100644
--- a/lib/src/room.dart
+++ b/lib/src/room.dart
@@ -478,7 +478,9 @@ class Room {
     Event inReplyTo,
     Map<String, dynamic> info,
     bool waitUntilSent = false,
-    int thumbnailSize = Client.defaultThumbnailSize,
+    int thumbnailMaxWidth = 800,
+    int thumbnailMaxHeight = 600,
+    int thumbnailQuality = 50,
   }) async {
     Image fileImage;
     Image thumbnailImage;
@@ -507,7 +509,11 @@ class Room {
       thumbnailPathParts.last = 'thumbnail_' + thumbnailPathParts.last + '.jpg';
       final thumbnailPath = thumbnailPathParts.join('/');
       thumbnail = MatrixFile(bytes: file.bytes, path: thumbnailPath);
-      await thumbnail.resize(width: thumbnailSize);
+      await thumbnail.resize(
+        width: thumbnailMaxWidth,
+        height: thumbnailMaxHeight,
+        quality: thumbnailQuality,
+      );
       fileImage = decodeImage(file.bytes.toList());
       thumbnailImage = decodeImage(thumbnail.bytes.toList());
     }
diff --git a/lib/src/utils/matrix_file.dart b/lib/src/utils/matrix_file.dart
index fd4a57a..93c8722 100644
--- a/lib/src/utils/matrix_file.dart
+++ b/lib/src/utils/matrix_file.dart
@@ -13,7 +13,11 @@ class MatrixFile {
   /// given width and height. Otherwise returns false.
   /// At least width or height must be set!
   /// The bytes will be encoded as jpg.
-  Future<bool> resize({int width, int height}) async {
+  Future<bool> resize({
+    int width,
+    int height,
+    int quality = 50,
+  }) async {
     if (width == null && height == null) {
       throw ('At least width or height must be set!');
     }
@@ -24,7 +28,7 @@ class MatrixFile {
       return false;
     }
     final resizedImage = copyResize(image, width: width, height: height);
-    bytes = encodeJpg(resizedImage, quality: 10);
+    bytes = encodeJpg(resizedImage, quality: quality);
     return true;
   }