diff --git a/httplib.h b/httplib.h
index 5c4e3b8..cb45f07 100644
--- a/httplib.h
+++ b/httplib.h
@@ -217,6 +217,14 @@ using socket_t = int;
 #include <thread>
 
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+// these are defined in wincrypt.h and it breaks compilation if BoringSSL is used
+#if defined(_WIN32)
+#undef X509_NAME
+#undef X509_CERT_PAIR
+#undef X509_EXTENSIONS
+#undef PKCS7_SIGNER_INFO
+#endif
+
 #include <openssl/err.h>
 #include <openssl/md5.h>
 #include <openssl/ssl.h>