diff --git a/src/circular_queue/MultiDelegate.h b/src/circular_queue/MultiDelegate.h
index d84c4c3..58af232 100644
--- a/src/circular_queue/MultiDelegate.h
+++ b/src/circular_queue/MultiDelegate.h
@@ -87,7 +87,7 @@ namespace detail
         };
     };
 
-    template< typename Delegate, typename R = void, bool ISQUEUE = false, unsigned QUEUE_CAPACITY = 32, typename... P>
+    template< typename Delegate, typename R = void, bool ISQUEUE = false, size_t QUEUE_CAPACITY = 32, typename... P>
     class MultiDelegatePImpl
     {
     public:
@@ -176,7 +176,7 @@ namespace detail
         Node_t* first = nullptr;
         Node_t* last = nullptr;
         Node_t* unused = nullptr;
-        unsigned nodeCount = 0;
+        size_t nodeCount = 0;
 
         // Returns a pointer to an unused Node_t,
         // or if none are available allocates a new one,
@@ -370,7 +370,7 @@ namespace detail
         }
     };
 
-    template< typename Delegate, typename R = void, bool ISQUEUE = false, unsigned QUEUE_CAPACITY = 32>
+    template< typename Delegate, typename R = void, bool ISQUEUE = false, size_t QUEUE_CAPACITY = 32>
     class MultiDelegateImpl : public MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY>
     {
     protected:
@@ -456,16 +456,16 @@ namespace detail
         }
     };
 
-    template< typename Delegate, typename R, bool ISQUEUE, unsigned QUEUE_CAPACITY, typename... P> class MultiDelegate;
+    template< typename Delegate, typename R, bool ISQUEUE, size_t QUEUE_CAPACITY, typename... P> class MultiDelegate;
 
-    template< typename Delegate, typename R, bool ISQUEUE, unsigned QUEUE_CAPACITY, typename... P>
+    template< typename Delegate, typename R, bool ISQUEUE, size_t QUEUE_CAPACITY, typename... P>
     class MultiDelegate<Delegate, R(P...), ISQUEUE, QUEUE_CAPACITY> : public MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY, P...>
     {
     public:
         using MultiDelegatePImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY, P...>::MultiDelegatePImpl;
     };
 
-    template< typename Delegate, typename R, bool ISQUEUE, unsigned QUEUE_CAPACITY>
+    template< typename Delegate, typename R, bool ISQUEUE, size_t QUEUE_CAPACITY>
     class MultiDelegate<Delegate, R(), ISQUEUE, QUEUE_CAPACITY> : public MultiDelegateImpl<Delegate, R, ISQUEUE, QUEUE_CAPACITY>
     {
     public:
@@ -493,7 +493,7 @@ It is designed to be used with Delegate, the efficient runtime wrapper for C fun
                allocates from the heap. Unused items are not returned to the heap, but are managed by the MultiDelegate
                instance during its own lifetime for efficiency.
 */
-template< typename Delegate, bool ISQUEUE = false, unsigned QUEUE_CAPACITY = 32>
+template< typename Delegate, bool ISQUEUE = false, size_t QUEUE_CAPACITY = 32>
 class MultiDelegate : public detail::MultiDelegate<Delegate, typename Delegate::target_type, ISQUEUE, QUEUE_CAPACITY>
 {
 public:
diff --git a/src/circular_queue/circular_queue.h b/src/circular_queue/circular_queue.h
index 46e3f66..e4fad8e 100644
--- a/src/circular_queue/circular_queue.h
+++ b/src/circular_queue/circular_queue.h
@@ -224,14 +224,14 @@ class circular_queue
 
 protected:
     const T defaultValue = {};
-    unsigned m_bufSize;
+    size_t m_bufSize;
 #if defined(ESP8266) || defined(ESP32) || !defined(ARDUINO)
     std::unique_ptr<T[]> m_buffer;
 #else
     std::unique_ptr<T> m_buffer;
 #endif
-    std::atomic<unsigned> m_inPos;
-    std::atomic<unsigned> m_outPos;
+    std::atomic<size_t> m_inPos;
+    std::atomic<size_t> m_outPos;
 };
 
 template< typename T, typename ForEachArg >
@@ -253,7 +253,7 @@ template< typename T, typename ForEachArg >
 bool IRAM_ATTR circular_queue<T, ForEachArg>::push()
 {
     const auto inPos = m_inPos.load(std::memory_order_acquire);
-    const unsigned next = (inPos + 1) % m_bufSize;
+    const size_t next = (inPos + 1) % m_bufSize;
     if (next == m_outPos.load(std::memory_order_relaxed)) {
         return false;
     }
@@ -268,7 +268,7 @@ template< typename T, typename ForEachArg >
 bool IRAM_ATTR circular_queue<T, ForEachArg>::push(T&& val)
 {
     const auto inPos = m_inPos.load(std::memory_order_acquire);
-    const unsigned next = (inPos + 1) % m_bufSize;
+    const size_t next = (inPos + 1) % m_bufSize;
     if (next == m_outPos.load(std::memory_order_relaxed)) {
         return false;
     }
diff --git a/src/circular_queue/ghostl.h b/src/circular_queue/ghostl.h
index 1168380..50f522c 100644
--- a/src/circular_queue/ghostl.h
+++ b/src/circular_queue/ghostl.h
@@ -26,6 +26,8 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include <atomic>
 #endif
 
+using size_t = decltype(sizeof(char));
+
 namespace std
 {
 #if !defined(ARDUINO_ARCH_SAMD)
@@ -48,7 +50,7 @@ namespace std
     template< typename T >	T&& move(T& t) noexcept { return static_cast<T&&>(t); }
 #endif
 
-    template< typename T, unsigned long N > struct array
+    template< typename T, size_t long N > struct array
     {
         T _M_elems[N];
         decltype(sizeof(0)) size() const { return N; }