diff --git a/uri.c b/uri.c
index a0e3838a..be1e0afe 100644
--- a/uri.c
+++ b/uri.c
@@ -266,7 +266,7 @@ err:
 bool
 hostname_is_localhost(const char *hostname)
 {
-    char this_host[HOST_NAME_MAX];
+    char this_host[_POSIX_HOST_NAME_MAX];
     if (gethostname(this_host, sizeof(this_host)) < 0)
         this_host[0] = '\0';