diff --git a/machines.lua b/machines.lua
index ce7a3c3..6a14a29 100644
--- a/machines.lua
+++ b/machines.lua
@@ -391,6 +391,11 @@ local function registerSimpleElectricItemProcessor(config)
 					meta:set_float("maxSrcTime",output.time*config.efficiency)
 				end
 			end
+			if srcSlot:get_count()==0 and meta:get_float("maxSrcTime")>0 then
+				meta:set_float("srcTime",-1)
+				meta:set_float("maxSrcTime",0)
+				shouldUpdateFormspec=true
+			end
 			if meta:get_float("maxSrcTime")>0 then
 				if meta:get_int("industrialtest.powerAmount")>=requiredPower then
 					meta:set_int("industrialtest.powerAmount",meta:get_int("industrialtest.powerAmount")-requiredPower)