diff --git a/include/etl/callback_timer.h b/include/etl/callback_timer.h
index 35022b55..26f4a116 100644
--- a/include/etl/callback_timer.h
+++ b/include/etl/callback_timer.h
@@ -43,8 +43,8 @@ SOFTWARE.
 #include <stdint.h>
 
 #if defined(ETL_IN_UNIT_TEST) && ETL_NOT_USING_STL
-  #define ETL_DISABLE_TIMER_UPDATES
-  #define ETL_ENABLE_TIMER_UPDATES
+  #define ETL_DISABLE_TIMER_UPDATES ((void)0)
+  #define ETL_ENABLE_TIMER_UPDATES  ((void)0)
   #define ETL_TIMER_UPDATES_ENABLED true
 
   #undef ETL_CALLBACK_TIMER_USE_ATOMIC_LOCK
@@ -59,8 +59,8 @@ SOFTWARE.
   #endif
 
   #if defined(ETL_CALLBACK_TIMER_USE_ATOMIC_LOCK)
-    #define ETL_DISABLE_TIMER_UPDATES (++process_semaphore);
-    #define ETL_ENABLE_TIMER_UPDATES  (--process_semaphore);
+    #define ETL_DISABLE_TIMER_UPDATES (++process_semaphore)
+    #define ETL_ENABLE_TIMER_UPDATES  (--process_semaphore)
     #define ETL_TIMER_UPDATES_ENABLED (process_semaphore.load() == 0)
   #endif
 #endif
@@ -70,8 +70,8 @@ SOFTWARE.
     #error ETL_CALLBACK_TIMER_DISABLE_INTERRUPTS and/or ETL_CALLBACK_TIMER_ENABLE_INTERRUPTS not defined
   #endif
 
-  #define ETL_DISABLE_TIMER_UPDATES ETL_CALLBACK_TIMER_DISABLE_INTERRUPTS;
-  #define ETL_ENABLE_TIMER_UPDATES  ETL_CALLBACK_TIMER_ENABLE_INTERRUPTS;
+  #define ETL_DISABLE_TIMER_UPDATES ETL_CALLBACK_TIMER_DISABLE_INTERRUPTS
+  #define ETL_ENABLE_TIMER_UPDATES  ETL_CALLBACK_TIMER_ENABLE_INTERRUPTS
   #define ETL_TIMER_UPDATES_ENABLED true
 #endif
 
@@ -195,10 +195,10 @@ namespace etl
         {
           if (timer.is_active())
           {
-            ETL_DISABLE_TIMER_UPDATES
+            ETL_DISABLE_TIMER_UPDATES;
             active_list.remove(timer.id, false);
             remove_callback.call_if(timer.id);
-            ETL_ENABLE_TIMER_UPDATES
+            ETL_ENABLE_TIMER_UPDATES;
           }
 
           // Reset in-place.
@@ -233,9 +233,9 @@ namespace etl
     //*******************************************
     void clear()
     {
-      ETL_DISABLE_TIMER_UPDATES
+      ETL_DISABLE_TIMER_UPDATES;
       active_list.clear();
-      ETL_ENABLE_TIMER_UPDATES
+      ETL_ENABLE_TIMER_UPDATES;
 
       for (int i = 0; i < MAX_TIMERS; ++i)
       {
@@ -333,7 +333,7 @@ namespace etl
           // Has a valid period.
           if (timer.period != etl::timer::state::Inactive)
           {
-            ETL_DISABLE_TIMER_UPDATES
+            ETL_DISABLE_TIMER_UPDATES;
             if (timer.is_active())
             {
               active_list.remove(timer.id, false);
@@ -343,7 +343,7 @@ namespace etl
             timer.delta = immediate_ ? 0 : timer.period;
             active_list.insert(timer.id);
             insert_callback.call_if(timer.id);
-            ETL_ENABLE_TIMER_UPDATES
+            ETL_ENABLE_TIMER_UPDATES;
 
             result = true;
           }
@@ -370,10 +370,10 @@ namespace etl
         {
           if (timer.is_active())
           {
-            ETL_DISABLE_TIMER_UPDATES
+            ETL_DISABLE_TIMER_UPDATES;
             active_list.remove(timer.id, false);
             remove_callback.call_if(timer.id);
-            ETL_ENABLE_TIMER_UPDATES
+            ETL_ENABLE_TIMER_UPDATES;
           }
 
           result = true;
diff --git a/include/etl/message_timer.h b/include/etl/message_timer.h
index ac0b54a3..8a458e65 100644
--- a/include/etl/message_timer.h
+++ b/include/etl/message_timer.h
@@ -44,8 +44,8 @@ SOFTWARE.
 #include <stdint.h>
 
 #if defined(ETL_IN_UNIT_TEST) && ETL_NOT_USING_STL
-  #define ETL_DISABLE_TIMER_UPDATES
-  #define ETL_ENABLE_TIMER_UPDATES
+  #define ETL_DISABLE_TIMER_UPDATES ((void)0)
+  #define ETL_ENABLE_TIMER_UPDATES  ((void)0)
   #define ETL_TIMER_UPDATES_ENABLED true
 
   #undef ETL_MESSAGE_TIMER_USE_ATOMIC_LOCK
@@ -60,8 +60,8 @@ SOFTWARE.
   #endif
 
   #if defined(ETL_MESSAGE_TIMER_USE_ATOMIC_LOCK)
-    #define ETL_DISABLE_TIMER_UPDATES (++process_semaphore);
-    #define ETL_ENABLE_TIMER_UPDATES  (--process_semaphore);
+    #define ETL_DISABLE_TIMER_UPDATES (++process_semaphore)
+    #define ETL_ENABLE_TIMER_UPDATES  (--process_semaphore)
     #define ETL_TIMER_UPDATES_ENABLED (process_semaphore.load() == 0)
   #endif
 
@@ -70,8 +70,8 @@ SOFTWARE.
       #error ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS and/or ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS not defined
     #endif
 
-    #define ETL_DISABLE_TIMER_UPDATES ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS;
-    #define ETL_ENABLE_TIMER_UPDATES  ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS;
+    #define ETL_DISABLE_TIMER_UPDATES ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS
+    #define ETL_ENABLE_TIMER_UPDATES  ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS
     #define ETL_TIMER_UPDATES_ENABLED true
   #endif
 #endif
@@ -390,10 +390,10 @@ namespace etl
         {
           if (timer.is_active())
           {
-            ETL_DISABLE_TIMER_UPDATES
+            ETL_DISABLE_TIMER_UPDATES;
             active_list.remove(timer.id, true);
             remove_callback.call_if(timer.id);
-            ETL_ENABLE_TIMER_UPDATES
+            ETL_ENABLE_TIMER_UPDATES;
           }
 
           // Reset in-place.
@@ -428,9 +428,9 @@ namespace etl
     //*******************************************
     void clear()
     {
-      ETL_DISABLE_TIMER_UPDATES
+      ETL_DISABLE_TIMER_UPDATES;
       active_list.clear();
-      ETL_ENABLE_TIMER_UPDATES
+      ETL_ENABLE_TIMER_UPDATES;
 
       for (int i = 0; i < Max_Timers; ++i)
       {
@@ -513,7 +513,7 @@ namespace etl
           // Has a valid period.
           if (timer.period != etl::timer::state::Inactive)
           {
-            ETL_DISABLE_TIMER_UPDATES
+            ETL_DISABLE_TIMER_UPDATES;
             if (timer.is_active())
             {
               active_list.remove(timer.id, false);
@@ -523,7 +523,7 @@ namespace etl
             timer.delta = immediate_ ? 0 : timer.period;
             active_list.insert(timer.id);
             insert_callback.call_if(timer.id);
-            ETL_ENABLE_TIMER_UPDATES
+            ETL_ENABLE_TIMER_UPDATES;
 
             result = true;
           }
@@ -550,10 +550,10 @@ namespace etl
         {
           if (timer.is_active())
           {
-            ETL_DISABLE_TIMER_UPDATES
+            ETL_DISABLE_TIMER_UPDATES;
             active_list.remove(timer.id, false);
             remove_callback.call_if(timer.id);
-            ETL_ENABLE_TIMER_UPDATES
+            ETL_ENABLE_TIMER_UPDATES;
           }
 
           result = true;
@@ -596,9 +596,9 @@ namespace etl
     //*******************************************
     bool has_active_timer() const
     {
-      ETL_DISABLE_TIMER_UPDATES
+      ETL_DISABLE_TIMER_UPDATES;
       bool result = !active_list.empty();
-      ETL_ENABLE_TIMER_UPDATES
+      ETL_ENABLE_TIMER_UPDATES;
 
       return result;
     }
@@ -612,12 +612,12 @@ namespace etl
     {
       uint32_t delta = static_cast<uint32_t>(etl::timer::interval::No_Active_Interval);
 
-      ETL_DISABLE_TIMER_UPDATES
+      ETL_DISABLE_TIMER_UPDATES;
       if (!active_list.empty())
       {
         delta = active_list.front().delta;
       }
-      ETL_ENABLE_TIMER_UPDATES
+      ETL_ENABLE_TIMER_UPDATES;
 
       return delta;
     }
diff --git a/test/syntax_check/etl_profile.h b/test/syntax_check/etl_profile.h
index ed633219..0346855e 100644
--- a/test/syntax_check/etl_profile.h
+++ b/test/syntax_check/etl_profile.h
@@ -33,11 +33,11 @@ SOFTWARE.
 #define ETL_TARGET_OS_NONE
 #define ETL_IN_UNIT_TEST
 #define ETL_CALLBACK_TIMER_USE_INTERRUPT_LOCK
-#define ETL_CALLBACK_TIMER_DISABLE_INTERRUPTS
-#define ETL_CALLBACK_TIMER_ENABLE_INTERRUPTS
+#define ETL_CALLBACK_TIMER_DISABLE_INTERRUPTS ((void)0)
+#define ETL_CALLBACK_TIMER_ENABLE_INTERRUPTS  ((void)0)
 #define ETL_MESSAGE_TIMER_USE_INTERRUPT_LOCK
-#define ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS
-#define ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS
+#define ETL_MESSAGE_TIMER_DISABLE_INTERRUPTS ((void)0)
+#define ETL_MESSAGE_TIMER_ENABLE_INTERRUPTS  ((void)0)
 
 #if defined(ETL_FORCE_TEST_CPP03_IMPLEMENTATION)
   #define ETL_FUNCTION_FORCE_CPP03_IMPLEMENTATION