diff --git a/zs.docs/SystemMastery/Production Speed for Buildings.md b/zs.docs/SystemMastery/Production Speed for Buildings.md
index 796eb7e..2646794 100644
--- a/zs.docs/SystemMastery/Production Speed for Buildings.md	
+++ b/zs.docs/SystemMastery/Production Speed for Buildings.md	
@@ -7,6 +7,7 @@ level_4: +1% Production speed for buildings
 level_5: +5% Production speed for buildings
 availableSystems:
   - "[[Endless Wastes]]"
+  - "[[Sullen Dwarf]]"
 productionSpeedForBuildings: 0.09
 ---
 9% production speed. Seems obvious for any tech up strategy.