diff --git a/include/orderqueue.hpp b/include/orderqueue.hpp
index bbe94c0..20cf7a0 100644
--- a/include/orderqueue.hpp
+++ b/include/orderqueue.hpp
@@ -26,11 +26,10 @@ class OrderQueue : public boost::intrusive::set_base_hook<boost::intrusive::opti
     [[nodiscard]] Decimal price() const;
     uint64_t len();
     [[nodiscard]] Decimal totalQty() const;
-    [[nodiscard]] Order *head();
-    [[nodiscard]] Order *tail();
     void append(Order *o);
     void remove(Order *o);
     Decimal process(const TradeNotification &tn, const PostOrderFill &postFill, OrderID takerOrderID, Decimal qty);
+    [[nodiscard]] const OrderList &order_list() const { return orders_; }
 
     friend bool operator<(const OrderQueue &a, const OrderQueue &b) { return a.price_ < b.price_; }
     friend bool operator>(const OrderQueue &a, const OrderQueue &b) { return a.price_ > b.price_; }
diff --git a/include/pricelevel.hpp b/include/pricelevel.hpp
index 14f8c07..a2cf469 100644
--- a/include/pricelevel.hpp
+++ b/include/pricelevel.hpp
@@ -55,7 +55,7 @@ class PriceLevel {
     template <PriceType Q = P>
     Decimal processLimitOrder(const TradeNotification& tn, const PostOrderFill& pf, OrderID takerOrderID, Decimal price, Decimal qty, Flag flag);
 
-    PriceTree& price_tree() { return price_tree_; };
+    const PriceTree& price_tree() const { return price_tree_; };
 };
 
 }  // namespace orderbook
diff --git a/src/orderqueue.cpp b/src/orderqueue.cpp
index cb1c824..456d4bf 100644
--- a/src/orderqueue.cpp
+++ b/src/orderqueue.cpp
@@ -10,10 +10,6 @@
 
 namespace orderbook {
 
-Order* OrderQueue::head() { return &orders_.front(); }
-
-Order* OrderQueue::tail() { return &orders_.back(); }
-
 Decimal OrderQueue::price() const { return price_; }
 
 Decimal OrderQueue::totalQty() const { return total_qty_; }
diff --git a/test/orderqueue_test.cpp b/test/orderqueue_test.cpp
index 62a7803..7e00b1b 100644
--- a/test/orderqueue_test.cpp
+++ b/test/orderqueue_test.cpp
@@ -4,9 +4,7 @@
 
 #include "util.cpp"
 
-namespace orderbook {
-
-namespace test {
+namespace orderbook::test {
 
 class OrderQueueTest : public ::testing::Test {
    protected:
@@ -25,8 +23,8 @@ TEST_F(OrderQueueTest, TestOrderQueue) {
     oq->append(&o1);
     oq->append(&o2);
 
-    auto* head = oq->head();
-    auto* tail = oq->tail();
+    auto* head = &oq->order_list().front();
+    auto* tail = &oq->order_list().back();
 
     ASSERT_NE(head, nullptr);
     ASSERT_NE(tail, nullptr);
@@ -36,8 +34,8 @@ TEST_F(OrderQueueTest, TestOrderQueue) {
 
     oq->remove(&o1);
 
-    ASSERT_EQ(oq->head(), &o2);
-    ASSERT_EQ(oq->head(), oq->tail());
+    ASSERT_EQ(&oq->order_list().front(), &o2);
+    ASSERT_EQ(oq->order_list().front(), oq->order_list().back());
 
     ASSERT_EQ(oq->len(), 1);
     ASSERT_EQ(oq->totalQty(), Decimal(100, 0));
@@ -46,6 +44,5 @@ TEST_F(OrderQueueTest, TestOrderQueue) {
     oq->remove(&o2);
 }
 
-}  // namespace test
-}  // namespace orderbook
+}  // namespace orderbook::test
 
diff --git a/test/pricelevel_test.cpp b/test/pricelevel_test.cpp
index 911160f..a60622b 100644
--- a/test/pricelevel_test.cpp
+++ b/test/pricelevel_test.cpp
@@ -43,10 +43,10 @@ TEST_F(PriceLevelTest, TestPriceLevel) {
     ASSERT_EQ(bidLevel.depth(), 2);
     ASSERT_EQ(bidLevel.len(), 2);
 
-    ASSERT_EQ(tree.begin()->head(), o2.get()) << "Invalid price levels: head of the first element does not match o1";
-    ASSERT_EQ(tree.begin()->tail(), o2.get()) << "Invalid price levels: tail of the first element does not match o1";
-    ASSERT_EQ(tree.rbegin()->head(), o1.get()) << "Invalid price levels: head of the last element does not match o2";
-    ASSERT_EQ(tree.rbegin()->tail(), o1.get()) << "Invalid price levels: tail of the last element does not match o2";
+    ASSERT_EQ(&tree.begin()->order_list().front(), o2.get()) << "Invalid price levels: head of the first element does not match o1";
+    ASSERT_EQ(&tree.begin()->order_list().back(), o2.get()) << "Invalid price levels: tail of the first element does not match o1";
+    ASSERT_EQ(&tree.rbegin()->order_list().front(), o1.get()) << "Invalid price levels: head of the last element does not match o2";
+    ASSERT_EQ(&tree.rbegin()->order_list().back(), o1.get()) << "Invalid price levels: tail of the last element does not match o2";
 
     bidLevel.remove(o1.get());