diff --git a/openflexure_microscope/camera/mock.py b/openflexure_microscope/camera/mock.py
index ec61bc7e..0b858cda 100644
--- a/openflexure_microscope/camera/mock.py
+++ b/openflexure_microscope/camera/mock.py
@@ -10,7 +10,6 @@ import time
 import numpy as np
 from PIL import Image, ImageFont, ImageDraw
 from datetime import datetime
-import gevent
 
 import logging
 
@@ -221,7 +220,7 @@ class MissingCamera(BaseCamera):
         # While the iterator is not closed
         try:
             while True:
-                gevent.sleep(1)  # Only serve frames at 1fps
+                time.sleep(1)  # Only serve frames at 1fps
                 # Reset stream
                 self.stream.seek(0)
                 self.stream.truncate()
diff --git a/openflexure_microscope/microscope.py b/openflexure_microscope/microscope.py
index 3df77eb1..1c55ac39 100644
--- a/openflexure_microscope/microscope.py
+++ b/openflexure_microscope/microscope.py
@@ -8,8 +8,6 @@ import uuid
 from typing import Tuple
 from expiringdict import ExpiringDict
 
-import gevent
-
 from openflexure_microscope.captures import CaptureManager
 
 from openflexure_microscope.stage.mock import MissingStage