diff --git a/src/libstrongswan/plugins/openssl/openssl_util.h b/src/libstrongswan/plugins/openssl/openssl_util.h
index ce2a9e109..2db073139 100644
--- a/src/libstrongswan/plugins/openssl/openssl_util.h
+++ b/src/libstrongswan/plugins/openssl/openssl_util.h
@@ -22,6 +22,12 @@
 #define OPENSSL_UTIL_H_
 
 #include <library.h>
+
+#ifdef X509_NAME
+/* from <wincrypt.h> */
+# undef X509_NAME
+#endif
+
 #include <openssl/bn.h>
 #include <openssl/asn1.h>