diff --git a/format.cc b/format.cc
index ab2a5b5a..4d1f9ff6 100644
--- a/format.cc
+++ b/format.cc
@@ -41,6 +41,7 @@
 #include <cstdarg>
 
 #ifdef _WIN32
+# define WIN32_LEAN_AND_MEAN
 # include <windows.h>
 # undef ERROR
 #endif