diff --git a/lib/control_flow.nom b/lib/control_flow.nom
index 825e1c2..2ac6cff 100644
--- a/lib/control_flow.nom
+++ b/lib/control_flow.nom
@@ -169,7 +169,7 @@ compile [when %body] to code:
             Invalid format for 'when' statement. Only '*' blocks are allowed.
         %tokens = (%func_call's "value")
         %star = (%tokens -> 1)
-        assert (=lua "vars.star and vars.star.type == 'Word' and vars.star.value == '*'") ".."
+        assert (=lua "\%star and \%star.type == 'Word' and \%star.value == '*'") ".."
             Invalid format for 'when' statement. Lines must begin with '*'
 
         %condition = (%tokens -> 2)
@@ -178,10 +178,10 @@ compile [when %body] to code:
 
         %action = (%tokens -> 3)
         if (%action == (nil)):
-            lua do> "table.insert(vars.fallthroughs, vars.condition)"
+            lua do> "table.insert(\%fallthroughs, \%condition)"
             do next %func_call
 
-        if (=lua "vars.condition.type == 'Word' and vars.condition.value == 'else'"):
+        if (=lua "\%condition.type == 'Word' and \%condition.value == 'else'"):
             %result join= ".."
                 
                 else
@@ -213,7 +213,7 @@ compile [when %branch_value == ? %body] to code:
             Invalid format for 'when' statement. Only '*' blocks are allowed.
         %tokens = (%func_call's "value")
         %star = (%tokens -> 1)
-        assert (=lua "vars.star and vars.star.type == 'Word' and vars.star.value == '*'") ".."
+        assert (=lua "\%star and \%star.type == 'Word' and \%star.value == '*'") ".."
             Invalid format for 'when' statement. Lines must begin with '*'
 
         %condition = (%tokens -> 2)
@@ -222,10 +222,10 @@ compile [when %branch_value == ? %body] to code:
 
         %action = (%tokens -> 3)
         if (%action == (nil)):
-            lua> "table.insert(vars.fallthroughs, vars.condition)"
+            lua> "table.insert(\%fallthroughs, \%condition)"
             do next %func_call
 
-        if (=lua "vars.condition.type == 'Word' and vars.condition.value == 'else'"):
+        if (=lua "\%condition.type == 'Word' and \%condition.value == 'else'"):
             %result join= ".."
                 
                 else
diff --git a/lib/operators.nom b/lib/operators.nom
index 23de2b3..9250214 100644
--- a/lib/operators.nom
+++ b/lib/operators.nom
@@ -62,7 +62,7 @@ lua do> ".."
             nomsu_alias, op = unpack(op);
         end
         nomsu:defmacro("%a "..nomsu_alias.." %b", (function(nomsu, vars)
-            return "("..nomsu:tree_to_lua(vars.a).." "..op.." "..nomsu:tree_to_lua(vars.b)..")";
+            return "("..nomsu:tree_to_lua(\%a).." "..op.." "..nomsu:tree_to_lua(\%b)..")";
         end), [["(\\%a ]]..op..[[ \\%b)"]]);
     end
 
@@ -112,7 +112,7 @@ lua do> ".."
                 -- Chained comparisons need to be functions to avoid re-evaluating their arguments :
                 nomsu:def(spec, function(nomsu, vars)
                     for i,op in ipairs(chain) do
-                        local a, b, result = vars[i], vars[i+1];
+                        local a, b, result = vars[tostring(i)], vars[tostring(i+1)];
                         if     op == "<"  then; result = a < b;
                         elseif op == "<=" then; result = a <= b;
                         elseif op == ">"  then; result = a > b;
diff --git a/lib/utils.nom b/lib/utils.nom
index a67b056..e46326e 100644
--- a/lib/utils.nom
+++ b/lib/utils.nom
@@ -16,8 +16,8 @@ parse [assert %condition] as: assert %condition (nil)
 rule [join %strs with glue %glue] =:
     lua do> ".."
         local str_bits = {}
-        for i,bit in ipairs(vars.strs) do str_bits[i] = nomsu:stringify(bit) end
-        return table.concat(str_bits, vars.glue)
+        for i,bit in ipairs(\%strs) do str_bits[i] = nomsu:stringify(bit) end
+        return table.concat(str_bits, \%glue)
 parse [join %strs] as: join %strs with glue ""
 
 compile [capitalize %str, %str capitalized] to:
diff --git a/lib/utils2.nom b/lib/utils2.nom
index d2fda8b..07ff008 100644
--- a/lib/utils2.nom
+++ b/lib/utils2.nom
@@ -24,7 +24,7 @@ compile [with %assignments %action] to code:
         %tokens = (%assignment's "value")
         %var = (%tokens -> 1)
         %eq = (%tokens -> 2)
-        assert (=lua "vars.eq and vars.eq.type == 'Word' and vars.eq.value == '='") ".."
+        assert (=lua "\%eq and \%eq.type == 'Word' and \%eq.value == '='") ".."
             Invalid format for 'with' statement. List entries must have the form %var = (value)
         %value = (%tokens -> 3)
         add {i=%i, var=%var, value=%value} to %data