diff --git a/src/backend/Makefile b/src/backend/Makefile
index 870a022..a991134 100644
--- a/src/backend/Makefile
+++ b/src/backend/Makefile
@@ -62,6 +62,8 @@ endif
 
 ifeq ($(PORTNAME), cygwin)
 
+LIBS += -lwsock32 -lws2_32
+
 postgres: $(OBJS)
 	$(CC) $(CFLAGS) $(LDFLAGS) $(LDFLAGS_EX) $(export_dynamic) -Wl,--stack,$(WIN32_STACK_RLIMIT) -Wl,--export-all-symbols -Wl,--out-implib=libpostgres.a $(call expand_subsys,$^) $(LIBS) -o $@