diff --git a/programs/aes/aescrypt2.c b/programs/aes/aescrypt2.c
index 59caf30..e6a243f 100644
--- a/programs/aes/aescrypt2.c
+++ b/programs/aes/aescrypt2.c
@@ -27,7 +27,7 @@
 #define _CRT_SECURE_NO_DEPRECATE 1
 #endif
 
-#if defined(WIN32)
+#if defined(_WIN32)
 #include <windows.h>
 #include <io.h>
 #else