diff --git a/uppsrc/Core/HeapImp.h b/uppsrc/Core/HeapImp.h
index 4fb81e353..f4f5ae867 100644
--- a/uppsrc/Core/HeapImp.h
+++ b/uppsrc/Core/HeapImp.h
@@ -1,8 +1,10 @@
-void *SysAllocRaw(size_t size);
+void  OutOfMemoryPanic(size_t size);
+
+void *SysAllocRaw(size_t size, int reqsize);
 void  SysFreeRaw(void *ptr, size_t size);
 
-void *AllocRaw4KB();
-void *AllocRaw64KB();
+void *AllocRaw4KB(int reqsize);
+void *AllocRaw64KB(int reqsize);
 void *LAlloc(size_t& size);
 void  LFree(void *ptr);
 
@@ -141,7 +143,7 @@ struct Heap {
 	static int  SizeToBin(int n) { return SzBin[(n - 1) >> 3]; }
 
 	void   LinkFree(DLink *b, int size);
-	DLink *AddChunk();
+	DLink *AddChunk(int reqsize);
 	void  *DivideBlock(DLink *b, int size, int ii);
 	void  *TryLAlloc(int ii, size_t size);
 	void  *LAlloc(size_t& size);
diff --git a/uppsrc/Core/heaputil.cpp b/uppsrc/Core/heaputil.cpp
index b4ab6b2fd..9198e0b14 100644
--- a/uppsrc/Core/heaputil.cpp
+++ b/uppsrc/Core/heaputil.cpp
@@ -19,7 +19,7 @@ void *MemoryAllocPermanentRaw(size_t size)
 	static byte *ptr = NULL;
 	static byte *limit = NULL;
 	if(ptr + size >= limit) {
-		ptr = (byte *)AllocRaw4KB();
+		ptr = (byte *)AllocRaw4KB(size);
 		limit = ptr + 4096;
 	}
 	void *p = ptr;
@@ -48,11 +48,19 @@ void DoPeakProfile()
 		heap.Make(*sPeak);
 }
 
+void OutOfMemoryPanic(size_t size)
+{
+	char h[200];
+	sprintf(h, "Out of memory!\nRequested size: %lld\nU++ allocated memory: %d KB",
+	        (long long)size, MemoryUsedKb());
+	Panic(h);
+}
+
 int sKB;
 
 int   MemoryUsedKb() { return sKB; }
 
-void *SysAllocRaw(size_t size)
+void *SysAllocRaw(size_t size, int reqsize)
 {
 	sKB += int(((size + 4095) & ~4095) >> 10);
 #ifdef PLATFORM_WIN32
@@ -67,7 +75,7 @@ void *SysAllocRaw(size_t size)
 		ptr = NULL;
 #endif
 	if(!ptr)
-		Panic("Out of memory!");
+		OutOfMemoryPanic((size_t)reqsize);
 	DoPeakProfile();
 	return ptr;
 }
@@ -85,14 +93,14 @@ void  SysFreeRaw(void *ptr, size_t size)
 int s4kb__;
 int s64kb__;
 
-void *AllocRaw4KB()
+void *AllocRaw4KB(int reqsize)
 {
 	static int   left;
 	static byte *ptr;
 	static int   n = 32;
 	if(left == 0) {
 		left = n >> 5;
-		ptr = (byte *)SysAllocRaw(left * 4096);
+		ptr = (byte *)SysAllocRaw(left * 4096, reqsize);
 	}
 	n = n + 1;
 	if(n > 4096) n = 4096;
@@ -104,14 +112,14 @@ void *AllocRaw4KB()
 	return p;
 }
 
-void *AllocRaw64KB()
+void *AllocRaw64KB(int reqsize)
 {
 	static int   left;
 	static byte *ptr;
 	static int   n = 32;
 	if(left == 0) {
 		left = n >> 5;
-		ptr = (byte *)SysAllocRaw(left * 65536);
+		ptr = (byte *)SysAllocRaw(left * 65536, reqsize);
 	}
 	n = n + 1;
 	if(n > 256) n = 256;
diff --git a/uppsrc/Core/lheap.cpp b/uppsrc/Core/lheap.cpp
index 44119e70a..77ffe0c61 100644
--- a/uppsrc/Core/lheap.cpp
+++ b/uppsrc/Core/lheap.cpp
@@ -50,7 +50,7 @@ void Heap::LinkFree(DLink *b, int size)
 	b->Link(freebin[q]);
 }
 
-Heap::DLink *Heap::AddChunk()
+Heap::DLink *Heap::AddChunk(int reqsize)
 {
 	DLink *ml;
 	if(lempty->next != lempty) {
@@ -59,7 +59,7 @@ Heap::DLink *Heap::AddChunk()
 		LLOG("Retrieved empty large " << (void *)ml);
 	}
 	else {
-		ml = (DLink *)AllocRaw64KB();
+		ml = (DLink *)AllocRaw64KB(reqsize);
 		LLOG("AllocRaw64KB " << (void *)ml);
 	}
 	lcount++;
@@ -157,9 +157,7 @@ void *Heap::LAlloc(size_t& size) {
 		Init();
 	if(size > MAXBLOCK) {
 		Mutex::Lock __(mutex);
-		BigHdr *h = (BigHdr *)SysAllocRaw(size + BIGHDRSZ);
-		if(!h)
-			Panic("Out of memory!");
+		BigHdr *h = (BigHdr *)SysAllocRaw(size + BIGHDRSZ, size);
 		h->Link(big);
 		h->size = size = ((size + BIGHDRSZ + 4095) & ~4095) - BIGHDRSZ;
 		Header *b = (Header *)((byte *)h + BIGHDRSZ - sizeof(Header));
@@ -188,7 +186,7 @@ void *Heap::LAlloc(size_t& size) {
 		ptr = TryLAlloc(bini, size);
 		if(ptr) return ptr;
 	}
-	DLink *n = AddChunk();
+	DLink *n = AddChunk(size);
 	if(!n)
 		Panic("Out of memory!");
 	ptr = DivideBlock(n, (int)size, LBINS - 1);
diff --git a/uppsrc/Core/sheap.cpp b/uppsrc/Core/sheap.cpp
index dfb1b2432..902761992 100644
--- a/uppsrc/Core/sheap.cpp
+++ b/uppsrc/Core/sheap.cpp
@@ -74,7 +74,7 @@ Heap::Page *Heap::WorkPage(int k)
 					break;
 				}
 		if(!page) {
-			page = (Page *)AllocRaw4KB();
+			page = (Page *)AllocRaw4KB(Ksz(k));
 			LLOG("AllocK - allocated new system page " << (void *)page << " " << k);
 			page->Format(k);
 		}