diff --git a/src/smalloc.h b/src/smalloc.h
index 97dda17b64..3321b4a895 100644
--- a/src/smalloc.h
+++ b/src/smalloc.h
@@ -24,10 +24,12 @@
 
 #include "node.h"
 #include "v8.h"
-#include "env.h"
 
 namespace node {
 
+// Forward declaration
+class Environment;
+
 /**
  * Simple memory allocator.
  *