diff --git a/scripts/http-server-header.nse b/scripts/http-server-header.nse
index 629175913..bb5be977a 100644
--- a/scripts/http-server-header.nse
+++ b/scripts/http-server-header.nse
@@ -30,22 +30,25 @@ action = function(host, port)
   local status, result = comm.tryssl(host, port,
     "GET / HTTP/1.0\r\n\r\n",
     {proto=port.protocol, timeout=5000})
-	
-	if (not status) then
-    return nil
-  end
 
-  local http_server = string.match(result, "\nServer:%s*(.-)\r?\n")
-  if http_server == nil then
+  if (not status) then
     return nil
   end
 
   port.version = port.version or {}
-  
+
+  if string.match(result, "^HTTP/1.[01] %d%d%d") then
+    port.version.service = "http"
+  else
+    return nil
+  end
+
+  local http_server = string.match(result, "\nServer:%s*(.-)\r?\n")
+
   if port.version.product == nil then
     port.version.product = http_server
   end
   nmap.set_port_version(host, port, "hardmatched")
-	
-	return
+
+  return
 end