1 files changed, 1 insertions, 0 deletions
diff --git a/random.c b/random.c
index 3fde5c3495..0ce2aef284 100644
--- a/random.c
+++ b/random.c
@@ -89,6 +89,7 @@ The original copyright notice follows.
 #  define _WIN32_WINNT 0x400
 #  undef __WINCRYPT_H__
 # endif
+#include <windows.h>
 #include <wincrypt.h>
 #endif
 #include "ruby_atomic.h"