diff --git a/gnu/services/web.scm b/gnu/services/web.scm
index 7e17dac6e2..53858436fa 100644
--- a/gnu/services/web.scm
+++ b/gnu/services/web.scm
@@ -668,6 +668,12 @@ (define (default-nginx-config config)
                                            '#$lua-package-cpath)
                                       ";"))
                "")
+           (if server-names-hash-bucket-size
+               (string-append
+                 "    server_names_hash_bucket_size "
+                 (number->string server-names-hash-bucket-size)
+                 ";\n")
+               "")
            (if server-names-hash-bucket-max-size
                (string-append
                 "    server_names_hash_bucket_max_size "