diff --git a/portable/GCC/ARM_CM0/portmacro.h b/portable/GCC/ARM_CM0/portmacro.h
index 41519997bd..bdc765803f 100644
--- a/portable/GCC/ARM_CM0/portmacro.h
+++ b/portable/GCC/ARM_CM0/portmacro.h
@@ -69,6 +69,9 @@ typedef unsigned long    UBaseType_t;
 /* 32-bit tick type on a 32-bit architecture, so reads of the tick count do
  * not need to be guarded with a critical section. */
     #define portTICK_TYPE_IS_ATOMIC    1
+#elif ( configTICK_TYPE_WIDTH_IN_BITS == TICK_TYPE_WIDTH_64_BITS )
+    typedef uint64_t     TickType_t;
+    #define portMAX_DELAY              ( TickType_t ) 0xffffffffffffffffULL
 #else
     #error configTICK_TYPE_WIDTH_IN_BITS set to unsupported tick type width.
 #endif
diff --git a/portable/GCC/ARM_CM33_NTZ/non_secure/portmacrocommon.h b/portable/GCC/ARM_CM33_NTZ/non_secure/portmacrocommon.h
index 33f21d85b6..17e3d40c7f 100644
--- a/portable/GCC/ARM_CM33_NTZ/non_secure/portmacrocommon.h
+++ b/portable/GCC/ARM_CM33_NTZ/non_secure/portmacrocommon.h
@@ -84,6 +84,9 @@ typedef unsigned long    UBaseType_t;
 /* 32-bit tick type on a 32-bit architecture, so reads of the tick count do
  * not need to be guarded with a critical section. */
     #define portTICK_TYPE_IS_ATOMIC    1
+#elif ( configTICK_TYPE_WIDTH_IN_BITS == TICK_TYPE_WIDTH_64_BITS )
+    typedef uint64_t     TickType_t;
+    #define portMAX_DELAY              ( TickType_t ) 0xffffffffffffffffULL
 #else
     #error configTICK_TYPE_WIDTH_IN_BITS set to unsupported tick type width.
 #endif
diff --git a/portable/MemMang/heap_4.c b/portable/MemMang/heap_4.c
index d2914bb792..b9b9aebf93 100644
--- a/portable/MemMang/heap_4.c
+++ b/portable/MemMang/heap_4.c
@@ -560,7 +560,7 @@ static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert ) /* PRIVI
 void vPortGetHeapStats( HeapStats_t * pxHeapStats )
 {
     BlockLink_t * pxBlock;
-    size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY used as a portable way of getting the maximum value. */
+    size_t xBlocks = 0, xMaxSize = 0, xMinSize = SIZE_MAX;
 
     vTaskSuspendAll();
     {