diff --git a/Tools/CodeGen/KrancThorn.m b/Tools/CodeGen/KrancThorn.m
index 311b63ff..8c257d73 100644
--- a/Tools/CodeGen/KrancThorn.m
+++ b/Tools/CodeGen/KrancThorn.m
@@ -135,7 +135,7 @@ Thorn generation (main entry point for non-tensorial thorns)
 
     CheckGroups[groupsOrig];
 
-    groups = Join[groupsOrig, {coordGroup}];
+    groups = Union[Join[groupsOrig, {coordGroup}]];
     includeFiles = Join[includeFiles, {"GenericFD.h", "Symmetry.h", "sbp_calc_coeffs.h"}];
 
     inheritedImplementations = Join[inheritedImplementations, {"Grid",
diff --git a/Tools/CodeGen/Schedule.m b/Tools/CodeGen/Schedule.m
index 08aa00ad..3bd64394 100644
--- a/Tools/CodeGen/Schedule.m
+++ b/Tools/CodeGen/Schedule.m
@@ -55,11 +55,20 @@
     eqs = lookup[calc, Equations];
     lhss = Map[First, eqs];
     gfsInLHS = Union[Cases[lhss, _ ? (MemberQ[gfs,#] &), Infinity]];
-
     lhsGroupNames = containingGroups[gfsInLHS, groups];
     Return[lhsGroupNames]
   ];
 
+groupsReadInCalc[calc_, groups_] :=
+  Module[{gfs, eqs, lhss, gfsInLHS, lhsGroupNames},
+    gfs = allGroupVariables[groups];
+    eqs = lookup[calc, Equations];
+    rhss = Map[Last, eqs];
+    gfsInRHS = Union[Cases[rhss, _ ? (MemberQ[gfs,#] &), Infinity]];
+    rhsGroupNames = containingGroups[gfsInRHS, groups];
+    Return[rhsGroupNames]
+  ];
+
 (* Each calculation can be scheduled at multiple points, so this
    function returns a LIST of schedule structures for each calculation
    *)
@@ -100,19 +109,13 @@
 
     (* TODO: Pass this as {keyword,value} pair instead of a string,
        once Thorn.m understands this format *)
-    (* TODO: This doesn't work -- I don't know how to access
-       OptionValue[] in this file.
     tags = If[OptionValue[UseOpenCL], "OpenCL=1", ""];
-    *)
-    tags = "OpenCL=1";
     
     prefixWithScope[group_] :=
       If[StringMatchQ[ToString[group], __~~"::"~~__],
          ToString[group],
          thornName <> "::" <> ToString[group]];
-    (* TODO: Don't blindly require/provide all groups, check the
-       equations instead *)
-    groupsToRequire = prefixWithScope /@ Map[First, groups];
+    groupsToRequire = prefixWithScope /@ groupsReadInCalc[calc, groups];
     groupsToProvide = prefixWithScope /@ groupsSetInCalc[calc, groups];
 
     before = lookupDefault[calc, Before, None];