diff --git a/library/cipher.c b/library/cipher.c
index 3ed6830..277811a 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -44,7 +44,7 @@
 #define POLARSSL_CIPHER_MODE_STREAM
 #endif
 
-#if defined _MSC_VER && !defined strcasecmp
+#if defined(_MSC_VER) && !defined strcasecmp
 #define strcasecmp _stricmp
 #endif