diff --git a/lib/isc/win32/include/isc/platform.h.in b/lib/isc/win32/include/isc/platform.h.in
index ac9b5e205d66a05dea2226795b7115518cd45f36..1ddadeb326fa6aa7f108853abdccfb0d3f9ea253 100644
--- a/lib/isc/win32/include/isc/platform.h.in
+++ b/lib/isc/win32/include/isc/platform.h.in
@@ -31,7 +31,7 @@
 #define ISC_PLATFORM_NEEDNTOP
 #define ISC_PLATFORM_NEEDPTON
 #define ISC_PLATFORM_HAVESOCKADDRSTORAGE
-#ifdef _MSC_VER >= 1900
+#if _MSC_VER >= 1900
 #define ISC_PLATFORM_HAVETFO
 #endif