diff --git a/portable/Heap/block_map.c b/portable/Heap/block_map.c
index b18c695e4..0c22243aa 100644
--- a/portable/Heap/block_map.c
+++ b/portable/Heap/block_map.c
@@ -10,7 +10,7 @@
 // Using
 //=======
 
-#include "heap_private.h"
+#include "block_map.h"
 #include "parent_group.h"
 
 
@@ -37,6 +37,8 @@ return block_map_parent_group_get_item((block_map_parent_group_t*)group, size);
 
 size_t block_map_group_get_last_size(block_map_group_t* group)
 {
+if(group==NULL)
+	return 0;
 if(cluster_group_get_level(group)==0)
 	return block_map_item_group_get_last_size((block_map_item_group_t*)group);
 return ((block_map_parent_group_t*)group)->last_size;
diff --git a/portable/Heap/cluster_group.h b/portable/Heap/cluster_group.h
index 77de128c5..aae948fd6 100644
--- a/portable/Heap/cluster_group.h
+++ b/portable/Heap/cluster_group.h
@@ -17,7 +17,7 @@
 // Using
 //=======
 
-#include "heap_internal.h"
+#include "heap.h"
 
 
 //=======
@@ -61,7 +61,7 @@ static inline uint16_t cluster_group_get_child_count(cluster_group_t* group)
 {
 cluster_group_t get;
 get.value=group->value;
-return get.child_count;
+return (uint16_t)get.child_count;
 }
 
 size_t cluster_group_get_item_count(cluster_group_t* group);
@@ -70,21 +70,21 @@ static inline uint16_t cluster_group_get_level(cluster_group_t* group)
 {
 cluster_group_t get;
 get.value=group->value;
-return get.level;
+return (uint16_t)get.level;
 }
 
 static inline bool cluster_group_is_dirty(cluster_group_t* group)
 {
 cluster_group_t get;
 get.value=group->value;
-return get.dirty;
+return (uint16_t)get.dirty;
 }
 
 static inline bool cluster_group_is_locked(cluster_group_t* group)
 {
 cluster_group_t get;
 get.value=group->value;
-return get.locked;
+return (uint16_t)get.locked;
 }
 
 
@@ -112,7 +112,7 @@ static inline void cluster_group_set_locked(cluster_group_t* group, bool lock)
 {
 cluster_group_t set;
 set.value=group->value;
-assert(set.locked!=lock);
+configASSERT((bool)set.locked!=lock);
 set.locked=lock;
 group->value=set.value;
 }
diff --git a/portable/Heap/heap.c b/portable/Heap/heap.c
index 58d1bbbe4..751549bd6 100644
--- a/portable/Heap/heap.c
+++ b/portable/Heap/heap.c
@@ -13,7 +13,7 @@
 // Using
 //=======
 
-#include "heap.h"
+#include "block_map.h"
 #include "semphr.h"
 
 
@@ -35,9 +35,6 @@
 #error Not supported with heap_6
 #endif
 
-/* Max value that fits in a size_t type. */
-#define SIZE_MAX (~(( size_t)0))
-
 /* Check if multiplying a and b will result in overflow. */
 #define MULTIPLY_WILL_OVERFLOW(a, b) (((a)>0)&&((b)>(SIZE_MAX/(a))))
 
@@ -114,13 +111,12 @@ heap->used=sizeof(heap_t);
 heap->size=size;
 heap->free_block=0;
 heap->next_heap=0;
-block_map_init(&heap->map_free);
+block_map_init((block_map_t*)&heap->map_free);
 if(prev_heap)
 	prev_heap->next_heap=(size_t)heap;
 xFreeBlocks++;
 xFreeBytes+=available;
-xLargestFreeBlock=max(xLargestFreeBlock, available);
-xMinimumFreeBytes=xFreeBytesAvailable;
+xMinimumFreeBytes=xFreeBytes;
 return heap;
 }
 
@@ -183,7 +179,7 @@ return heap_block_init(heap, &info);
 void* heap_alloc_from_map(heap_handle_t heap, size_t size)
 {
 heap_block_info_t info;
-if(!block_map_get_block(heap, &heap->map_free, size, &info))
+if(!block_map_get_block(heap, (block_map_t*)&heap->map_free, size, &info))
 	return NULL;
 heap->free-=info.size;
 heap_reduce_free_bytes(info.size);
@@ -245,7 +241,7 @@ if(info.previous.free)
 	{
 	offset=info.previous.offset;
 	size+=info.previous.size;
-	block_map_remove_block(heap, &heap->map_free, &info.previous);
+	block_map_remove_block(heap, (block_map_t*)&heap->map_free, &info.previous);
 	heap->free-=info.previous.size;
 	xFreeBlocks--;
 	xFreeBytes-=info.previous.size;
@@ -260,7 +256,7 @@ if(!info.next.offset)
 if(info.next.free)
 	{
 	size+=info.next.size;
-	block_map_remove_block(heap, &heap->map_free, &info.next);
+	block_map_remove_block(heap, (block_map_t*)&heap->map_free, &info.next);
 	heap->free-=info.next.size;
 	xFreeBlocks--;
 	xFreeBytes-=info.next.size;
@@ -272,7 +268,7 @@ info.current.offset=offset;
 info.current.size=size;
 info.current.free=true;
 heap_block_init(heap, &info.current);
-block_map_add_block(heap, &heap->map_free, &info.current);
+block_map_add_block(heap, (block_map_t*)&heap->map_free, &info.current);
 }
 
 
@@ -283,7 +279,7 @@ block_map_add_block(heap, &heap->map_free, &info.current);
 size_t heap_get_largest_free_block(heap_handle_t heap)
 {
 size_t largest=0;
-largest=block_map_get_last_size(heap->map_free);
+largest=block_map_get_last_size((block_map_t*)&heap->map_free);
 largest=max(largest, heap->size-heap->used);
 return largest;
 }
@@ -302,7 +298,7 @@ if(MULTIPLY_WILL_OVERFLOW(xNum, xSize)==0)
 	if(buf!=NULL)
 		memset(buf, 0, xNum*xSize);
 	}
-return pv;
+return buf;
 }
 
 void* pvPortMalloc(size_t xWantedSize)
@@ -328,7 +324,6 @@ void vPortDefineHeapRegions(HeapRegion_t const* pxHeapRegions)PRIVILEGED_FUNCTIO
 {
 configASSERT(first_heap==NULL);
 configASSERT(pxHeapRegions!=NULL);
-BaseType_t heap_count=0;
 HeapRegion_t const* region=pxHeapRegions;
 while(region->xSizeInBytes>0)
 	{
@@ -341,7 +336,9 @@ while(region->xSizeInBytes>0)
 	last_heap=heap;
 	region++;
 	}
+#if(configUSE_HEAP_IN_ISR==0)
 heap_mutex=xSemaphoreCreateMutexStatic(&heap_mutex_buf);
+#endif
 }
 
 void vPortFree(void* pv)
@@ -395,8 +392,10 @@ heap_unlock(locked);
 
 void vPortHeapResetState(void)
 {
+#if(configUSE_HEAP_IN_ISR==0)
 vSemaphoreDelete(heap_mutex);
 heap_mutex=NULL;
+#endif
 first_heap=NULL;
 last_heap=NULL;
 xFreeBlocks=0;
diff --git a/portable/Heap/heap.h b/portable/Heap/heap.h
index f5eae8b09..1ba9724cd 100644
--- a/portable/Heap/heap.h
+++ b/portable/Heap/heap.h
@@ -17,8 +17,46 @@
 // Using
 //=======
 
-#include "block_map.h"
-#include "offset_index.h"
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+#include "FreeRTOS.h"
+#include "task.h"
+
+#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+
+//==========
+// Settings
+//==========
+
+#define configUSE_HEAP_IN_ISR 1
+
+#define CLUSTER_GROUP_SIZE 10
+
+
+//===========
+// Alignment
+//===========
+
+#define SIZE_BITS (sizeof(size_t)*8)
+#define SIZE_BYTES sizeof(size_t)
+
+#define BLOCK_SIZE_MIN (4*SIZE_BYTES)
+
+static inline size_t align_down(size_t value, size_t align)
+{
+return value&~(align-1);
+}
+
+static inline size_t align_up(size_t value, size_t align)
+{
+return value+(align-value%align)%align;
+}
 
 
 //======
@@ -32,7 +70,7 @@ size_t used;
 size_t size;
 size_t free_block;
 size_t next_heap;
-block_map_t map_free;
+size_t map_free;
 }heap_t;
 
 typedef heap_t* heap_handle_t;
diff --git a/portable/Heap/heap_block.c b/portable/Heap/heap_block.c
index cfbf59f6e..3b015995c 100644
--- a/portable/Heap/heap_block.c
+++ b/portable/Heap/heap_block.c
@@ -10,7 +10,7 @@
 // Using
 //=======
 
-#include "heap.h"
+#include "heap_block.h"
 
 
 //==================
diff --git a/portable/Heap/heap_block.h b/portable/Heap/heap_block.h
index 7e4f8ced2..e913cfa49 100644
--- a/portable/Heap/heap_block.h
+++ b/portable/Heap/heap_block.h
@@ -17,7 +17,7 @@
 // Using
 //=======
 
-#include "heap_internal.h"
+#include "heap.h"
 
 
 //======
diff --git a/portable/Heap/heap_internal.h b/portable/Heap/heap_internal.h
deleted file mode 100644
index c43fb0463..000000000
--- a/portable/Heap/heap_internal.h
+++ /dev/null
@@ -1,57 +0,0 @@
-//=================
-// heap_internal.h
-//=================
-
-// Copyright 2024, Sven Bieg (svenbieg@web.de)
-// http://github.com/svenbieg/Heap
-
-#ifndef _HEAP_INTERNAL_H
-#define _HEAP_INTERNAL_H
-
-
-//=======
-// Using
-//=======
-
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
-
-#include "FreeRTOS.h"
-#include "task.h"
-
-#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
-
-
-//==========
-// Settings
-//==========
-
-#define configUSE_HEAP_IN_ISR 1
-
-#define CLUSTER_GROUP_SIZE 10
-
-
-//===========
-// Alignment
-//===========
-
-#define SIZE_BITS (sizeof(size_t)*8)
-#define SIZE_BYTES sizeof(size_t)
-
-#define BLOCK_SIZE_MIN (4*SIZE_BYTES)
-
-static inline size_t align_down(size_t value, size_t align)
-{
-return value&~(align-1);
-}
-
-static inline size_t align_up(size_t value, size_t align)
-{
-return value+(align-value%align)%align;
-}
-
-#endif // _HEAP_INTERNAL_H
diff --git a/portable/Heap/offset_index.c b/portable/Heap/offset_index.c
index 3709f9c5a..3e1bc7195 100644
--- a/portable/Heap/offset_index.c
+++ b/portable/Heap/offset_index.c
@@ -11,6 +11,7 @@
 //=======
 
 #include "heap.h"
+#include "offset_index.h"
 #include "parent_group.h"
 
 
diff --git a/portable/Heap/parent_group.c b/portable/Heap/parent_group.c
index c63989286..9854e023a 100644
--- a/portable/Heap/parent_group.c
+++ b/portable/Heap/parent_group.c
@@ -10,7 +10,6 @@
 // Using
 //=======
 
-#include "heap_private.h"
 #include "parent_group.h"
 
 
diff --git a/portable/Heap/parent_group.h b/portable/Heap/parent_group.h
index feea43ed1..1166fded6 100644
--- a/portable/Heap/parent_group.h
+++ b/portable/Heap/parent_group.h
@@ -16,7 +16,6 @@
 // Using
 //=======
 
-#include <heap.h>
 #include "cluster_group.h"