diff --git a/uppsrc/Core/HeapImp.h b/uppsrc/Core/HeapImp.h
index 12128ae7a..2cebe43d8 100644
--- a/uppsrc/Core/HeapImp.h
+++ b/uppsrc/Core/HeapImp.h
@@ -1,6 +1,4 @@
-void  OutOfMemoryPanic();
-
-void *SysAllocRaw(size_t size, size_t reqsize);
+void *SysAllocRaw(size_t size);
 void  SysFreeRaw(void *ptr, size_t size);
 
 const char *asString(int i);
diff --git a/uppsrc/Core/heaputil.cpp b/uppsrc/Core/heaputil.cpp
index 99eaa48ac..74aa47011 100644
--- a/uppsrc/Core/heaputil.cpp
+++ b/uppsrc/Core/heaputil.cpp
@@ -12,8 +12,12 @@ namespace Upp {
 
 void OutOfMemoryPanic(size_t size)
 {
-	char h[200];
-	snprintf(h, 200, "Out of memory!\nU++ allocated memory: %d KB", MemoryUsedKb());
+	char h[1024];
+	snprintf(h, 200,
+		"Out of memory!\n"
+		"U++ allocated memory (including failed request): %zu KB\n"
+		"System allocation request: %zu (0x%zx)\n",
+		4 * (Heap::huge_4KB_count - Heap::free_4KB), size, size);
 	Panic(h);
 }
 
@@ -36,7 +40,7 @@ int MemoryUsedKbMax()
 	return int(4 * Heap::huge_4KB_count_max);
 }
 
-void *SysAllocRaw(size_t size, size_t reqsize)
+void *SysAllocRaw(size_t size)
 {
 	void *ptr = NULL;
 #ifdef PLATFORM_WIN32
@@ -68,12 +72,12 @@ void *MemoryAllocPermanent(size_t size)
 {
 	Mutex::Lock __(Heap::mutex);
 	if(size > 10000)
-		return SysAllocRaw(size, size);
+		return SysAllocRaw(size);
 	static byte *ptr = NULL;
 	static byte *limit = NULL;
 	ASSERT(size < INT_MAX);
 	if(!ptr || ptr + size >= limit) {
-		ptr = (byte *)SysAllocRaw(16384, 16384);
+		ptr = (byte *)SysAllocRaw(16384);
 		limit = ptr + 16384;
 	}
 	void *p = ptr;
diff --git a/uppsrc/Core/hheap.cpp b/uppsrc/Core/hheap.cpp
index b98870332..d0d2760c0 100644
--- a/uppsrc/Core/hheap.cpp
+++ b/uppsrc/Core/hheap.cpp
@@ -30,7 +30,7 @@ EXITBLOCK {
 }
 #endif
 
-size_t sKBLimit = INT_MAX;
+size_t sKBLimit = SIZE_MAX;
 
 void  MemoryLimitKb(int kb)
 {
@@ -80,7 +80,7 @@ void *Heap::HugeAlloc(size_t count) // count in 4kb pages
 		
 	if(count > sys_block_limit) { // we are wasting 4KB to store just 4 bytes here, but this is n MB after all..
 		LTIMING("SysAlloc");
-		byte *sysblk = (byte *)SysAllocRaw((count + 1) * 4096, 0);
+		byte *sysblk = (byte *)SysAllocRaw((count + 1) * 4096);
 		BlkHeader *h = (BlkHeader *)(sysblk + 4096);
 		h->size = 0;
 		*((size_t *)sysblk) = count;
@@ -112,7 +112,7 @@ void *Heap::HugeAlloc(size_t count) // count in 4kb pages
 		}
 
 		if(!FreeSmallEmpty(wcount, INT_MAX)) { // try to coalesce 4KB small free blocks back to huge storage
-			void *ptr = SysAllocRaw(HPAGE * 4096, 0); // failed, add HPAGE from the system
+			void *ptr = SysAllocRaw(HPAGE * 4096); // failed, add HPAGE from the system
 
 			HugePage *pg; // record in set of huge pages
 			if(free_huge_pages) {