diff --git a/queue.c b/queue.c
index d2e27e55a..b01dfd11f 100644
--- a/queue.c
+++ b/queue.c
@@ -397,6 +397,9 @@ BaseType_t xQueueGenericReset( QueueHandle_t xQueue,
         /* Check for multiplication overflow. */
         configASSERT( ( uxItemSize == 0 ) || ( uxQueueLength == ( xQueueSizeInBytes / uxItemSize ) ) );
 
+        /* Check for addition overflow. */
+        configASSERT( ( sizeof( Queue_t ) + xQueueSizeInBytes ) >  xQueueSizeInBytes );
+
         /* Allocate the queue and storage area.  Justification for MISRA
          * deviation as follows:  pvPortMalloc() always ensures returned memory
          * blocks are aligned per the requirements of the MCU stack.  In this case
diff --git a/stream_buffer.c b/stream_buffer.c
index 03cfc0615..fec03a781 100644
--- a/stream_buffer.c
+++ b/stream_buffer.c
@@ -258,8 +258,16 @@ static void prvInitialiseNewStreamBuffer( StreamBuffer_t * const pxStreamBuffer,
          * this is a quirk of the implementation that means otherwise the free
          * space would be reported as one byte smaller than would be logically
          * expected. */
-        xBufferSizeBytes++;
-        pucAllocatedMemory = ( uint8_t * ) pvPortMalloc( xBufferSizeBytes + sizeof( StreamBuffer_t ) ); /*lint !e9079 malloc() only returns void*. */
+        if( xBufferSizeBytes < ( xBufferSizeBytes + 1 + sizeof( StreamBuffer_t ) ) )
+        {
+            xBufferSizeBytes++;
+            pucAllocatedMemory = ( uint8_t * ) pvPortMalloc( xBufferSizeBytes + sizeof( StreamBuffer_t ) ); /*lint !e9079 malloc() only returns void*. */
+        }
+        else
+        {
+            pucAllocatedMemory = NULL;
+        }
+        
 
         if( pucAllocatedMemory != NULL )
         {