diff --git a/examples/ArmTimerCallbacks - C++/ArmTimerCallbacks.uvprojx b/examples/ArmTimerCallbacks - C++/ArmTimerCallbacks.uvprojx
index ed494f20..b7fa094b 100644
--- a/examples/ArmTimerCallbacks - C++/ArmTimerCallbacks.uvprojx	
+++ b/examples/ArmTimerCallbacks - C++/ArmTimerCallbacks.uvprojx	
@@ -336,7 +336,7 @@
               <MiscControls></MiscControls>
               <Define></Define>
               <Undefine></Undefine>
-              <IncludePath>..\..\src;..\ArmTimerCallbacks - C++</IncludePath>
+              <IncludePath>..\..\include;..\ArmTimerCallbacks - C++</IncludePath>
             </VariousControls>
           </Cads>
           <Aads>
diff --git a/examples/ArmTimerCallbacks - C++/etl_profile.h b/examples/ArmTimerCallbacks - C++/etl_profile.h
index 4560ba1e..a2e2f33f 100644
--- a/examples/ArmTimerCallbacks - C++/etl_profile.h	
+++ b/examples/ArmTimerCallbacks - C++/etl_profile.h	
@@ -9,13 +9,14 @@
 #define ETL_IVECTOR_REPAIR_ENABLE
 #define ETL_IDEQUE_REPAIR_ENABLE
 #define ETL_IN_UNIT_TEST
+#define ETL_CALLBACK_TIMER_USE_ATOMIC_LOCK
 
 #if (__CC_ARM == 1)
   // ARM5 compiler
-  #include "profiles/armv5.h"
+  #include "etl/profiles/armv5.h"
 #else
   // ARM6 compiler
-  #include "profiles/armv6.h"
+  #include "etl/profiles/armv6.h"
 #endif
 
 #endif
diff --git a/examples/ArmTimerCallbacks - C++/main.cpp b/examples/ArmTimerCallbacks - C++/main.cpp
index 05f19b17..d2d0e5a3 100644
--- a/examples/ArmTimerCallbacks - C++/main.cpp	
+++ b/examples/ArmTimerCallbacks - C++/main.cpp	
@@ -9,8 +9,23 @@ extern "C"
   #include "stm32f4xx.h"     // Device header
 }
 
-#include "function.h"
-#include "callback_timer.h"
+#include "etl/function.h"
+#include "etl/callback_timer.h"
+#include "etl/vector.h"
+
+struct FP
+{
+  void (*function)();
+};
+
+static etl::vector<FP, 10> power_callbacks;
+
+void register_poweroff_callback(void (*function)()) 
+{
+  FP fp = { function };
+  power_callbacks.push_back(fp);
+}
+
 
 const int N_TIMERS = 4;
 
diff --git a/include/etl/atomic/atomic_gcc_sync.h b/include/etl/atomic/atomic_gcc_sync.h
index d26005b2..725c44ac 100644
--- a/include/etl/atomic/atomic_gcc_sync.h
+++ b/include/etl/atomic/atomic_gcc_sync.h
@@ -34,7 +34,7 @@ SOFTWARE.
 #include "../static_assert.h"
 #include "../nullptr.h"
 
-#include <stdatomic.h>
+//#include <stdatomic.h>
 #include <stdint.h>
 
 #pragma GCC diagnostic push
diff --git a/include/etl/debug_count.h b/include/etl/debug_count.h
index b603b00c..66b40530 100644
--- a/include/etl/debug_count.h
+++ b/include/etl/debug_count.h
@@ -84,25 +84,15 @@ namespace etl
       return *this;
     }
 
-    inline debug_count& operator +=(int32_t n)
-    {
-      count += n;
-      return *this;
-    }
-
-    inline debug_count& operator -=(int32_t n)
-    {
-      count -= n;
-      return *this;
-    }
-
-    inline debug_count& operator +=(size_t n)
+    template <typename T>
+    inline debug_count& operator +=(T n)
     {
       count += int32_t(n);
       return *this;
     }
 
-    inline debug_count& operator -=(size_t n)
+    template <typename T>
+    inline debug_count& operator -=(T n)
     {
       count -= int32_t(n);
       return *this;
diff --git a/include/etl/stl/iterator.h b/include/etl/stl/iterator.h
index 91299a26..56f2e5d6 100644
--- a/include/etl/stl/iterator.h
+++ b/include/etl/stl/iterator.h
@@ -40,4 +40,4 @@ SOFTWARE.
   #include <iterator>
 #endif
 
-#endif
\ No newline at end of file
+#endif
diff --git a/include/etl/version.h b/include/etl/version.h
index 531de754..a89a8969 100644
--- a/include/etl/version.h
+++ b/include/etl/version.h
@@ -37,10 +37,10 @@ SOFTWARE.
 /// Definitions of the ETL version
 ///\ingroup utilities
 
-#define ETL_VERSION      "11.15.0"
-#define ETL_VERSION_W   L"11.15.0"
-#define ETL_VERSION_U16 u"11.15.0"
-#define ETL_VERSION_U32 U"11.15.0"
+#define ETL_VERSION      "11.15.1"
+#define ETL_VERSION_W   L"11.15.1"
+#define ETL_VERSION_U16 u"11.15.1"
+#define ETL_VERSION_U32 U"11.15.1"
 #define ETL_VERSION_MAJOR 11
 #define ETL_VERSION_MINOR 15
 #define ETL_VERSION_PATCH  0
diff --git a/support/Release notes.txt b/support/Release notes.txt
index fde6c598..f977f9d7 100644
--- a/support/Release notes.txt	
+++ b/support/Release notes.txt	
@@ -1,3 +1,8 @@
+===============================================================================
+11.15.1
+io_port_test Fixed unaligned access error.
+debug_count  Removed typed += & -= operators and replaced with templates.
+
 ===============================================================================
 11.15.0
 Added 'memory model' selection for queues to allow more efficient implementations.
diff --git a/test/test_io_port.cpp b/test/test_io_port.cpp
index 88223339..4634e8da 100644
--- a/test/test_io_port.cpp
+++ b/test/test_io_port.cpp
@@ -95,7 +95,14 @@ namespace
     //*************************************************************************
     TEST(test_dynamic_io_port)
     {
-      uint8_t memory[7];
+      union U
+      {
+        uint16_t dummy;
+        uint8_t memory[7];
+      } u;
+
+      uint8_t* memory = &u.memory[0];
+
       memory[0] = 0x12;
       memory[1] = 0x00;
       memory[2] = 0x00;
@@ -104,7 +111,7 @@ namespace
       memory[5] = 0x9A;
       memory[6] = 0x00;
 
-      dynamic_serial_port port(memory);
+      dynamic_serial_port port(&u.memory[0]);
 
       uint8_t rxdata = port.rxdata;
       CHECK_EQUAL(memory[0], rxdata);