diff --git a/src/msafd.h b/src/msafd.h
index 11f79a8..e6e88a0 100644
--- a/src/msafd.h
+++ b/src/msafd.h
@@ -1,7 +1,8 @@
 #ifndef EPOLL_MSAFD_H_
 #define EPOLL_MSAFD_H_
 
-#include <windows.h>
+#include <Windows.h>
+
 #include "ntapi.h"
 
 #ifndef SIO_BASE_HANDLE
diff --git a/src/ntapi.h b/src/ntapi.h
index 0fd6588..e1eba9d 100644
--- a/src/ntapi.h
+++ b/src/ntapi.h
@@ -1,7 +1,7 @@
 #ifndef EPOLL_NTAPI_H_
 #define EPOLL_NTAPI_H_
 
-#include <windows.h>
+#include <Windows.h>
 
 #ifndef _NTDEF_
 typedef LONG NTSTATUS;