diff --git a/build.cpp b/build.cpp
index 29e1292..4a07e75 100644
--- a/build.cpp
+++ b/build.cpp
@@ -1,5 +1,6 @@
 #define EXT_LINK
 #define EXT_INC
+#define Wextra
 #include "build.hpp"
 #include <unordered_set>