diff --git a/watcher/app.py b/watcher/app.py
index 6ce918e..8466250 100644
--- a/watcher/app.py
+++ b/watcher/app.py
@@ -13,7 +13,7 @@ from flask_cors import CORS
 
 sio = socketio.Server()
 app = Flask(__name__)
-cors = CORS(app)
+CORS(app)
 app.wsgi_app = socketio.WSGIApp(sio, app.wsgi_app)
 
 # We request users to send the run number to prevent accidentially getting old requests from a previous run
@@ -38,6 +38,9 @@ def index():
 
 @app.route("/start_run/<run_index>")
 def start_run(run_index):
+    if not run_index.isdigit():
+        return f'{run_index} is not a number'
+
     db["current_run"] = run_index
     starttime = time()
     if run_index in db["run_data"]:
@@ -50,6 +53,9 @@ def start_run(run_index):
 
 @app.route("/link/start/<run>/<link_index>")
 def link_start(run, link_index):
+    if not run.isdigit() or not link_index.isdigit():
+        return f'{run} and/or {link_index} is not a number'
+
     start = time()
     request_data = live_request(run, link_index)
     sio.emit('live_request', request_data)
@@ -72,6 +78,9 @@ def link_start(run, link_index):
 
 @app.route("/link/handoff/<run>/<index>")
 def link_handoff(run, index):
+    if not run.isdigit() or not index.isdigit():
+        return f'{run} and/or {index} is not a number'
+
     if db["current_run"] != run:
         return "Wrong run number, check that you updated you run", 404
     else: