diff --git a/lib/src/client.dart b/lib/src/client.dart
index e463e5d..71035d6 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -135,7 +135,7 @@ class Client {
   bool get encryptionEnabled => _olmAccount != null;
 
   /// Whether this client is able to encrypt and decrypt files.
-  bool get fileEncryptionEnabled => false;
+  bool get fileEncryptionEnabled => true;
 
   /// Warning! This endpoint is for testing only!
   set rooms(List<Room> newList) {
@@ -877,15 +877,15 @@ class Client {
 
   /// Uploads a file with the name [fileName] as base64 encoded to the server
   /// and returns the mxc url as a string.
-  Future<String> upload(MatrixFile file) async {
+  Future<String> upload(MatrixFile file, {String contentType}) async {
     // For testing
     if (this.homeserver.toLowerCase() == "https://fakeserver.notexisting") {
       return "mxc://example.com/AQwafuaFswefuhsfAFAgsw";
     }
     Map<String, String> headers = {};
     headers["Authorization"] = "Bearer $accessToken";
-    headers["Content-Type"] = mime(file.path);
-    String fileName = file.path.split("/").last.toLowerCase();
+    headers["Content-Type"] = contentType ?? mime(file.path);
+    String fileName = Uri.encodeFull(file.path.split("/").last.toLowerCase());
     final url = "$homeserver/_matrix/media/r0/upload?filename=$fileName";
     final streamedRequest = http.StreamedRequest('POST', Uri.parse(url))
       ..headers.addAll(headers);
@@ -897,6 +897,10 @@ class Client {
     Map<String, dynamic> jsonResponse = json.decode(
       String.fromCharCodes(await streamedResponse.stream.first),
     );
+    if (!(jsonResponse["content_uri"] is String &&
+        jsonResponse["content_uri"].isNotEmpty)) {
+      throw ("Missing json key: 'content_uri' ${jsonResponse.toString()}");
+    }
     return jsonResponse["content_uri"];
   }
 
diff --git a/lib/src/room.dart b/lib/src/room.dart
index 651c5d0..9c309c4 100644
--- a/lib/src/room.dart
+++ b/lib/src/room.dart
@@ -481,7 +481,10 @@ class Room {
     if (sendEncrypted) {
       encryptedFile = await file.encrypt();
     }
-    final String uploadResp = await client.upload(file);
+    final String uploadResp = await client.upload(
+      file,
+      contentType: sendEncrypted ? "application/octet-stream" : null,
+    );
 
     // Send event
     Map<String, dynamic> content = {
diff --git a/lib/src/utils/matrix_file.dart b/lib/src/utils/matrix_file.dart
index 11b0ea7..a85fba0 100644
--- a/lib/src/utils/matrix_file.dart
+++ b/lib/src/utils/matrix_file.dart
@@ -8,10 +8,10 @@ class MatrixFile {
   Uint8List bytes;
   String path;
 
+  /// Encrypts this file, changes the [bytes] and returns the
+  /// encryption information as an [EncryptedFile].
   Future<EncryptedFile> encrypt() async {
-    print("[Matrix] Encrypt file with a size of ${bytes.length} bytes");
     final EncryptedFile encryptedFile = await encryptFile(bytes);
-    print("[Matrix] File encryption successfull");
     this.bytes = encryptedFile.data;
     return encryptedFile;
   }
diff --git a/pubspec.lock b/pubspec.lock
index 0b20c5d..30ef5f6 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -257,7 +257,7 @@ packages:
     dependency: "direct main"
     description:
       path: "."
-      ref: "1.x.y"
+      ref: HEAD
       resolved-ref: b043fcc29031979dc65e5b08e10ebb9b8d2fae30
       url: "https://gitlab.com/famedly/libraries/matrix_file_e2ee.git"
     source: git
diff --git a/pubspec.yaml b/pubspec.yaml
index 2d97306..e3c0281 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -20,7 +20,7 @@ dependencies:
   matrix_file_e2ee:
     git:
       url: https://gitlab.com/famedly/libraries/matrix_file_e2ee.git
-      ref: 1.x.y
+      #ref: 1.x.y
 
 dev_dependencies:
   test: ^1.0.0