diff --git a/helper.py b/helper.py
index 7c0cc7e..9a29051 100755
--- a/helper.py
+++ b/helper.py
@@ -48,7 +48,7 @@
 wait_between_attempts = 0.1
 
 picture_watcher.watch(
-    alias="image", path=img_input_file, flags=aionotify.Flags.MODIFY
+    alias="image", path=img_input_file, flags=aionotify.Flags.CLOSE_WRITE
 )  # sets up watcher
 
 
diff --git a/shepherd/blueprints/upload/__init__.py b/shepherd/blueprints/upload/__init__.py
index 952a181..145d0ea 100644
--- a/shepherd/blueprints/upload/__init__.py
+++ b/shepherd/blueprints/upload/__init__.py
@@ -25,15 +25,11 @@ def upload():
         file = request.files["uploaded_file"]
     except KeyError:
         abort(400)
-    if file.filename == "":
-        flash("You didn't upload a file.", "error")
-    else:
-        flash("Got a file with filename {}".format(file.filename), "debug")
+    if file.filename != "":
         err = process_uploaded_file(file)
         if err:
-            flash(err, "error")
+            return f"{err}", 400
         else:
-            flash("Your file looks good!", "success")  # TODO: run a linter on the code?
             run.send("upload")
     return "", 204