diff --git a/reactos/drivers/filesystems/btrfs/fileinfo.c b/reactos/drivers/filesystems/btrfs/fileinfo.c
index 3fc654e31f8..9f6e54f41fe 100644
--- a/reactos/drivers/filesystems/btrfs/fileinfo.c
+++ b/reactos/drivers/filesystems/btrfs/fileinfo.c
@@ -1893,7 +1893,13 @@ static NTSTATUS STDCALL stream_set_end_of_file_information(device_extension* Vcb
             free_traverse_ptr(&tp);
             return STATUS_INTERNAL_ERROR;
         }
-        
+
+#ifdef __REACTOS__
+        // BUGBUG: FIXME!!
+        ERR("BUGBUG: datalen is uninitialized! Set it to zero temporarily...\n");
+        datalen = 0;
+#endif
+
         if (tp.item->size < datalen) {
             ERR("(%llx,%x,%llx) was %u bytes, expected at least %u\n", tp.item->key.obj_id, tp.item->key.obj_type, tp.item->key.offset, tp.item->size, datalen);
             free_traverse_ptr(&tp);
diff --git a/reactos/lib/drivers/ntoskrnl_vista/CMakeLists.txt b/reactos/lib/drivers/ntoskrnl_vista/CMakeLists.txt
index 05237020cf2..39d9d1279c8 100644
--- a/reactos/lib/drivers/ntoskrnl_vista/CMakeLists.txt
+++ b/reactos/lib/drivers/ntoskrnl_vista/CMakeLists.txt
@@ -1,7 +1,7 @@
 remove_definitions(-D_WIN32_WINNT=0x502)
 add_definitions(-D_WIN32_WINNT=0x600)
 
-add_definitions(-DUNICODE -D_UNICODE)
+add_definitions(-DUNICODE -D_UNICODE -D__NTOSKRNL__ -D_NTOSKRNL_ -D_NTSYSTEM_)
 
 list(APPEND SOURCE
     fsrtl.c