diff --git a/ngx_http_auth_digest_module.h b/ngx_http_auth_digest_module.h
index 6694354..3e8c97b 100644
--- a/ngx_http_auth_digest_module.h
+++ b/ngx_http_auth_digest_module.h
@@ -50,7 +50,7 @@ typedef struct {
   ngx_rbtree_node_t node; // the node's .key is derived from the source address
   time_t drop_time;
   ngx_int_t failcount;
-  struct sockaddr src_addr;
+  struct sockaddr_storage src_addr;
   socklen_t src_addrlen;
 } ngx_http_auth_digest_ev_node_t;