diff --git a/script/state_manager.js b/script/state_manager.js
index e07ea37..c6455fe 100644
--- a/script/state_manager.js
+++ b/script/state_manager.js
@@ -342,9 +342,20 @@ var StateManager = {
 				
 				if(income.timeLeft <= 0) {
 					Engine.log('collection income from ' + source);
-					if(source == 'thieves')	$SM.addStolen(income.stores);
-					$SM.addM('stores', income.stores, true);
-					changed = true;
+					if(source == 'thieves')	$SM.addStolen(income.stores);
+
+					var cost = income.stores;
+					var ok = true;
+					for(var k in cost) {
+						var have = $SM.get('stores["'+k+'"]', true);
+						if(have + cost[k] < 0) {
+							if(source != 'thieves') ok = false;
+						}
+					}
+					if(ok){
+						$SM.addM('stores', income.stores, true);
+					}
+					changed = true;
 					if(typeof income.delay == 'number') {
 						income.timeLeft = income.delay;
 					}