diff --git a/binaries/data/mods/public/simulation/ai/petra/headquarters.js b/binaries/data/mods/public/simulation/ai/petra/headquarters.js
index ed0ba75ed7..a3914d13b0 100644
--- a/binaries/data/mods/public/simulation/ai/petra/headquarters.js
+++ b/binaries/data/mods/public/simulation/ai/petra/headquarters.js
@@ -1805,7 +1805,7 @@ m.HQ.prototype.canBuild = function(gameState, structure)
 	// build limits
 	var limits = gameState.getEntityLimits();
 	var category = template.buildCategory();
-	if (category && limits[category] && gameState.getEntityCounts()[category] >= limits[category])
+	if (category && limits[category] !== undefined && gameState.getEntityCounts()[category] >= limits[category])
 		return false;
 
 	return true;