diff --git a/CHANGELOG b/CHANGELOG
index f613d2bdb..894a1290e 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -7,7 +7,8 @@ o A new script argument, http.useragent, gives the ability to modify
   the User-Agent header sent by NSE from its default of "Mozilla/5.0
   (compatible; Nmap Scripting Engine; http://nmap.org/book/nse.html)".
   You can set it to the empty string to disable the User-Agent
-  entirely. [David]
+  entirely. A bug was found and fixed by Tom Sellers and Jah,
+  respectively. [David]
 
 o [Nmat] The --ssl, --output, and --hex-dump options now work with
   --exec and --sh-exec. This is done by forking a separate process to
diff --git a/nselib/http.lua b/nselib/http.lua
index 8363ff541..d1cdfc91f 100644
--- a/nselib/http.lua
+++ b/nselib/http.lua
@@ -42,7 +42,7 @@ local have_ssl = (nmap.have_ssl() and pcall(require, "openssl"))
 
 local USER_AGENT
 do
-  local arg = nmap.registry.args["http.useragent"]
+  local arg = nmap.registry.args and nmap.registry.args["http.useragent"]
   if arg and arg == "" then
     USER_AGENT = nil
   elseif arg then