diff --git a/mlist_to_mml.lua b/mlist_to_mml.lua
index eb4f13d..3eed3b8 100644
--- a/mlist_to_mml.lua
+++ b/mlist_to_mml.lua
@@ -67,8 +67,8 @@ local function noad_to_table(noad, sub, cur_style)
 
     if (noad.sup or noad.sub) and (class == 'opdisplaylimits' or class == 'oplimits') then
       nucleus.movablelimits = class == 'opdisplaylimits'
-      local sub = kernel_to_table(nucleus.sub, sub_style(cur_style))
-      local sup = kernel_to_table(nucleus.sup, sup_style(cur_style))
+      local sub = kernel_to_table(noad.sub, sub_style(cur_style))
+      local sup = kernel_to_table(noad.sup, sup_style(cur_style))
       return {[0] = sup and (sub and 'munderover' or 'mover') or 'munder',
         nucleus,
         sub or sup,
diff --git a/test_tex.tex b/test_tex.tex
index 2f7f692..37c78bc 100644
--- a/test_tex.tex
+++ b/test_tex.tex
@@ -9,6 +9,6 @@
   x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}.
 \]
 \[
-  a\dot bc'
+  \sum_a\underline c\dot bc'
 \]
 \end{document}