diff --git a/scripts/dns-nsec-enum.nse b/scripts/dns-nsec-enum.nse
index 2f0c38082..10b5b95ec 100644
--- a/scripts/dns-nsec-enum.nse
+++ b/scripts/dns-nsec-enum.nse
@@ -88,7 +88,7 @@ local function split(domain)
 end
 
 local function join(components)
-  return table.concat(remove_empty(components, "."))
+  return table.concat(remove_empty(components), ".")
 end
 
 -- Remove the first component of a domain name. Return nil if the number of
diff --git a/scripts/dns-nsec3-enum.nse b/scripts/dns-nsec3-enum.nse
index 3f3983549..1932ce5e6 100644
--- a/scripts/dns-nsec3-enum.nse
+++ b/scripts/dns-nsec3-enum.nse
@@ -108,7 +108,7 @@ local function split(domain)
 end
 
 local function join(components)
-  return table.concat(remove_empty(components, "."))
+  return table.concat(remove_empty(components), ".")
 end
 
 -- Remove the first component of a domain name. Return nil if the number of