diff --git a/lib/includes/ngtcp2/ngtcp2.h b/lib/includes/ngtcp2/ngtcp2.h
index abef3855bebd6a1f473f717612a06c2675b3fbde..3373adb9f91a52c1d0907a68d338da5b81e3d8f9 100644
--- a/lib/includes/ngtcp2/ngtcp2.h
+++ b/lib/includes/ngtcp2/ngtcp2.h
@@ -46,10 +46,15 @@ extern "C" {
 #  include <inttypes.h>
 #endif /* !defined(_MSC_VER) || (_MSC_VER >= 1800) */
 #include <sys/types.h>
-#include <sys/socket.h>
 #include <stdarg.h>
 #include <stddef.h>
 
+#ifdef WIN32
+#  include <winsock2.h>
+#else
+#  include <sys/socket.h>
+#endif
+
 #include <ngtcp2/version.h>
 
 #ifdef NGTCP2_STATICLIB
diff --git a/lib/ngtcp2_addr.c b/lib/ngtcp2_addr.c
index cf7a4f317b6d5394cf28efcf488f20a533615be7..cfc91c41e2c38e84279f63ee44982700fcb64d0f 100644
--- a/lib/ngtcp2_addr.c
+++ b/lib/ngtcp2_addr.c
@@ -26,7 +26,18 @@
 
 #include <string.h>
 #include <assert.h>
-#include <netinet/ip.h>
+
+#ifdef WIN32
+#  include <winsock2.h>
+#  include <ws2tcpip.h>
+#else
+#  include <sys/types.h>
+#  include <sys/socket.h>
+#  include <netinet/in.h>
+#  include <netinet/ip.h>
+#  include <netinet/tcp.h>
+#  include <arpa/inet.h>
+#endif
 
 ngtcp2_addr *ngtcp2_addr_init(ngtcp2_addr *dest, const struct sockaddr *addr,
                               size_t addrlen, void *user_data) {