diff --git a/include/binder/IpPrefix.h b/include/binder/IpPrefix.h
index f8c80dc..96ebaac 100644
--- a/include/binder/IpPrefix.h
+++ b/include/binder/IpPrefix.h
@@ -71,6 +71,7 @@
 
 private:
     union InternalUnion {
+        InternalUnion() = default;
         InternalUnion(const struct in6_addr &addr):mIn6Addr(addr) { };
         InternalUnion(const struct in_addr &addr):mInAddr(addr) { };
         struct in6_addr mIn6Addr;