diff --git a/src/ursaNative.h b/src/ursaNative.h
index f16f9a5..c1bc84a 100644
--- a/src/ursaNative.h
+++ b/src/ursaNative.h
@@ -3,7 +3,9 @@
 #ifndef URSA_NATIVE_H
 #define URSA_NATIVE_H
 
+#ifndef BUILDING_NODE_EXTENSION
 #define BUILDING_NODE_EXTENSION
+#endif
 #include <node.h>
 #include <v8.h>