diff --git a/src/subprocess_windows.h b/src/subprocess_windows.h
index 42aaa41f5..40b5a0904 100644
--- a/src/subprocess_windows.h
+++ b/src/subprocess_windows.h
@@ -3,6 +3,7 @@
 
 #include "subprocess.h"
 
+#include <windows.h>
 #include <synchapi.h>
 
 class WinImpl : public SubprocessImpl