diff --git a/android/src/main/java/com/bluechilli/flutteruploader/UploadWorker.java b/android/src/main/java/com/bluechilli/flutteruploader/UploadWorker.java
index 5ea424d..6681e75 100644
--- a/android/src/main/java/com/bluechilli/flutteruploader/UploadWorker.java
+++ b/android/src/main/java/com/bluechilli/flutteruploader/UploadWorker.java
@@ -317,11 +317,15 @@ private Result handleException(Context context, Exception ex, String code) {
   }
 
   private String GetMimeType(String url) {
-    String type = "*/*";
+    String type = "application/octet-stream";
     String extension = MimeTypeMap.getFileExtensionFromUrl(url);
     try {
       if (extension != null && !extension.isEmpty()) {
-        type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase());
+        String mimeType =
+            MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase());
+        if (mimeType != null && !mimeType.isEmpty()) {
+          type = mimeType;
+        }
       }
     } catch (Exception ex) {
       Log.d(TAG, "UploadWorker - GetMimeType", ex);