diff --git a/portable/MemMang/heap_4.c b/portable/MemMang/heap_4.c
index 8ca7c81e4..c7a8209ed 100644
--- a/portable/MemMang/heap_4.c
+++ b/portable/MemMang/heap_4.c
@@ -159,13 +159,31 @@ void * pvPortMalloc( size_t xWantedSize )
         if( xWantedSize > 0 )
         {
             /* The wanted size must be increased so it can contain a BlockLink_t
-             * structure in addition to the requested amount of bytes. Some
-             * additional increment may also be needed for alignment. */
-            xAdditionalRequiredSize = xHeapStructSize + portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK );
-
-            if( heapADD_WILL_OVERFLOW( xWantedSize, xAdditionalRequiredSize ) == 0 )
+             * structure in addition to the requested amount of bytes. */
+            if( heapADD_WILL_OVERFLOW( xWantedSize, xHeapStructSize ) == 0 )
             {
-                xWantedSize += xAdditionalRequiredSize;
+                xWantedSize += xHeapStructSize;
+
+                /* Ensure that blocks are always aligned to the required number
+                 * of bytes. */
+                if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+                {
+                    /* Byte alignment required. */
+                    xAdditionalRequiredSize = portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK );
+
+                    if( heapADD_WILL_OVERFLOW( xWantedSize, xAdditionalRequiredSize ) == 0 )
+                    {
+                        xWantedSize += xAdditionalRequiredSize;
+                    }
+                    else
+                    {
+                        xWantedSize = 0;
+                    }
+                }
+                else
+                {
+                    mtCOVERAGE_TEST_MARKER();
+                }
             }
             else
             {
diff --git a/portable/MemMang/heap_5.c b/portable/MemMang/heap_5.c
index 3a1df9b64..db9e1eb37 100644
--- a/portable/MemMang/heap_5.c
+++ b/portable/MemMang/heap_5.c
@@ -170,13 +170,31 @@ void * pvPortMalloc( size_t xWantedSize )
         if( xWantedSize > 0 )
         {
             /* The wanted size must be increased so it can contain a BlockLink_t
-             * structure in addition to the requested amount of bytes. Some
-             * additional increment may also be needed for alignment. */
-            xAdditionalRequiredSize = xHeapStructSize + portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK );
-
-            if( heapADD_WILL_OVERFLOW( xWantedSize, xAdditionalRequiredSize ) == 0 )
+             * structure in addition to the requested amount of bytes. */
+            if( heapADD_WILL_OVERFLOW( xWantedSize, xHeapStructSize ) == 0 )
             {
-                xWantedSize += xAdditionalRequiredSize;
+                xWantedSize += xHeapStructSize;
+
+                /* Ensure that blocks are always aligned to the required number
+                 * of bytes. */
+                if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+                {
+                    /* Byte alignment required. */
+                    xAdditionalRequiredSize = portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK );
+
+                    if( heapADD_WILL_OVERFLOW( xWantedSize, xAdditionalRequiredSize ) == 0 )
+                    {
+                        xWantedSize += xAdditionalRequiredSize;
+                    }
+                    else
+                    {
+                        xWantedSize = 0;
+                    }
+                }
+                else
+                {
+                    mtCOVERAGE_TEST_MARKER();
+                }
             }
             else
             {