diff --git a/scripts/reverse-index.nse b/scripts/reverse-index.nse
index 51248fe1b..f1e079684 100644
--- a/scripts/reverse-index.nse
+++ b/scripts/reverse-index.nse
@@ -136,6 +136,10 @@ end
 
 postaction = function()
 	local db = nmap.registry[SCRIPT_NAME]
+	if ( db == nil ) then
+		return false
+	end
+  
 	local results
 	local mode = stdnse.get_script_args("reverse-index.mode") or "horizontal"