diff --git a/config-msvc.h b/config-msvc.h
index 0ae38482..b08beb52 100644
--- a/config-msvc.h
+++ b/config-msvc.h
@@ -40,6 +40,7 @@
 #define HAVE_IN_PKTINFO 1
 
 #define HAVE_OPENSSL_ENGINE 1
+#define HAVE_EXPORT_KEYING_MATERIAL 1
 
 #define HAVE_DIINSTALLDEVICE 1