diff --git a/vm/code_heap.cpp b/vm/code_heap.cpp
index b7aa9185e8..9e64ff6552 100755
--- a/vm/code_heap.cpp
+++ b/vm/code_heap.cpp
@@ -5,7 +5,7 @@ namespace factor
 
 code_heap::code_heap(cell size)
 {
-	if(size > (1L << (sizeof(cell) * 8 - 6))) fatal_error("Heap too large",size);
+	if(size > ((u64)1 << (sizeof(cell) * 8 - 6))) fatal_error("Heap too large",size);
 	seg = new segment(align_page(size),true);
 	if(!seg) fatal_error("Out of memory in heap allocator",size);
 	allocator = new free_list_allocator<code_block>(size,seg->start);
diff --git a/vm/os-windows-nt.hpp b/vm/os-windows-nt.hpp
index 5b55ce1f2b..f8407aeee5 100755
--- a/vm/os-windows-nt.hpp
+++ b/vm/os-windows-nt.hpp
@@ -23,8 +23,13 @@ FACTOR_STDCALL LONG exception_handler(PEXCEPTION_POINTERS pe);
 
 // SSE traps raise these exception codes, which are defined in internal NT headers
 // but not winbase.h
+#ifndef STATUS_FLOAT_MULTIPLE_FAULTS
 #define STATUS_FLOAT_MULTIPLE_FAULTS 0xC00002B4
+#endif
+
+#ifndef STATUS_FLOAT_MULTIPLE_TRAPS
 #define STATUS_FLOAT_MULTIPLE_TRAPS  0xC00002B5
+#endif
 
 typedef HANDLE THREADHANDLE;