diff --git a/sopel_modules/SpiceBot/Events.py b/sopel_modules/SpiceBot/Events.py
index 8d8e031..23a28f0 100644
--- a/sopel_modules/SpiceBot/Events.py
+++ b/sopel_modules/SpiceBot/Events.py
@@ -106,7 +106,9 @@ class BotEvents(object):
         self.lock.acquire()
         if not isinstance(startlist, list):
             startlist = [str(startlist)]
-        self.dict["startup_required"].extend(startlist)
+        for eventitem in startlist:
+            if eventitem not in self.dict["startup_required"]:
+                self.dict["startup_required"].append(eventitem)
         self.lock.release()
 
     def startup_check(self):