diff --git a/minecart/monitoring.lua b/minecart/monitoring.lua
index bde3fcd..c25f231 100644
--- a/minecart/monitoring.lua
+++ b/minecart/monitoring.lua
@@ -256,11 +256,13 @@ minetest.register_chatcommand("stopcart", {
 					local entity = minetest.luaentities[data.objID]
 					if entity then  -- cart entity running
 						minecart.entity_to_node(player_pos, entity)
+						minecart.monitoring_remove_cart(owner, userID)
 					end
 				else
 					local pos = data.last_pos or data.pos
-					local cargo, owner, userID = minecart.remove_nodecart(pos)
+					local cargo, _, _ = minecart.remove_nodecart(pos)
 					minecart.add_nodecart(player_pos, data.node_name, 0, cargo, owner, userID)
+					minecart.monitoring_remove_cart(owner, userID)
 				end
 				return true, S("Cart") .. " " .. userID .. " " .. S("stopped")
 			else
diff --git a/ta4_jetpack/init.lua b/ta4_jetpack/init.lua
index 0c63ee6..cc29bd0 100644
--- a/ta4_jetpack/init.lua
+++ b/ta4_jetpack/init.lua
@@ -231,7 +231,7 @@ minetest.register_globalstep(function(dtime)
 			if ctrl > 0 then
 				minetest.add_particle({
 					pos = pos,
-					vel = {x = vel.x, y = vel.y - 10, z = vel.z},
+					velocity = {x = vel.x, y = vel.y - 10, z = vel.z},
 					expirationtime = 1,
 					size = 5,
 					vertical = false,