diff --git a/src/openttd.cpp b/src/openttd.cpp
index 275a8d1d0c..4cb5d17752 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -1489,6 +1489,11 @@ void CheckCaches(bool force_check)
 			assert(memcmp(&st->goods[c].cargo, buff, sizeof(StationCargoList)) == 0);
 		}
 	}
+
+	OrderList *order_list;
+	FOR_ALL_ORDER_LISTS(order_list) {
+		order_list->DebugCheckSanity();
+	}
 }
 
 /**
diff --git a/src/order_base.h b/src/order_base.h
index 5db0ab3774..f3d93726f2 100644
--- a/src/order_base.h
+++ b/src/order_base.h
@@ -701,6 +701,7 @@ public:
 	void FreeChain(bool keep_orderlist = false);
 
 	void DebugCheckSanity() const;
+	bool CheckOrderListIndexing() const;
 
 	/**
 	 * Get the vector of all scheduled dispatch slot
diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index 5749828f43..2aa18693cd 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -371,6 +371,16 @@ void OrderList::ReindexOrderList()
 	}
 }
 
+bool OrderList::CheckOrderListIndexing() const
+{
+	uint idx = 0;
+	for (Order *o = this->first; o != nullptr; o = o->next, idx++) {
+		if (idx >= this->order_index.size()) return false;
+		if (this->order_index[idx] != o) return false;
+	}
+	return idx == this->order_index.size();
+}
+
 /**
  * Recomputes everything.
  * @param chain first order in the chain
@@ -778,6 +788,7 @@ void OrderList::DebugCheckSanity() const
 	DEBUG(misc, 6, "... detected %u orders (%u manual), %u vehicles, %i timetabled, %i total",
 			(uint)this->GetNumOrders(), (uint)this->num_manual_orders,
 			this->num_vehicles, this->timetable_duration, this->total_duration);
+	assert(this->CheckOrderListIndexing());
 }
 
 /**