diff --git a/src/node.cc b/src/node.cc
index dd05fb9a30f..c764a5761e9 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -26,7 +26,8 @@ using namespace std;
 static void
 buf_free (evnet_buf *b)
 {
-  V8::AdjustAmountOfExternalAllocatedMemory(-b->len);
+  size_t total = sizeof(evnet_buf) + b->len;
+  V8::AdjustAmountOfExternalAllocatedMemory(-total);
   free(b);
 }