diff --git a/nselib/strict.lua b/nselib/strict.lua
index bcb88f545..a5c4e2bd5 100644
--- a/nselib/strict.lua
+++ b/nselib/strict.lua
@@ -60,7 +60,7 @@ function strict ()
     if type(_index) == "function" then
       local v = _index(t, n); -- hook it
       if v ~= nil then return v end
-    else
+    elseif _index ~= nil then
       local v = _index[n];
       if v ~= nil then return v end
     end