diff --git a/Resources/Prototypes/GameRules/roundstart.yml b/Resources/Prototypes/GameRules/roundstart.yml
index 066bf9b626..7d1128a416 100644
--- a/Resources/Prototypes/GameRules/roundstart.yml
+++ b/Resources/Prototypes/GameRules/roundstart.yml
@@ -60,6 +60,8 @@
   components:
   - type: NukeopsRule
     faction: Syndicate
+  - type: ThiefRule #the thieves come as an extension of another gamemode
+    ruleChance: 0.5
 
 - type: entity
   id: Pirates