diff --git a/tinygrad/uop/spec.py b/tinygrad/uop/spec.py
index 084c110d99..a010d082fb 100644
--- a/tinygrad/uop/spec.py
+++ b/tinygrad/uop/spec.py
@@ -44,6 +44,10 @@ try:
       UOp(Ops.NOOP, arg=z3.Bool(f"float_cmp{ctx[1].setdefault(x, len(ctx[1]))}",ctx=ctx[0].ctx))),
   ])
 
+  def uops_to_z3(solver, *uops: UOp) -> 'list[z3.ExprRef]':
+    with Context(TRACK_MATCH_STATS=0):  # cant pickle z3 objects
+      return [s.arg for s in graph_rewrite(uops[0].sink(*uops[1:]), z3_renderer, ctx=(solver, {})).src]
+
   z3_imported = True
 except (ImportError, AttributeError): z3_imported = False
 
@@ -124,9 +128,8 @@ def validate_index(idx:UOp, gate:UOp=UOp.const(dtypes.bool, True)):
 
   if not z3_imported: raise ImportError("z3 is required for bounds checking, try IGNORE_OOB=0 or \"pip install z3-solver\"")
   solver = z3.Solver(ctx=z3.Context())
-  z3_sink = graph_rewrite(idx.src[1].sink(mask), z3_renderer, ctx=(solver, {}))
-  z3_idx = z3_sink.src[0].arg
-  solver.add(z3_sink.src[1].arg)
+  z3_idx, z3_mask = uops_to_z3(solver, idx.src[1], mask)
+  solver.add(z3_mask)
   if solver.check((z3_idx<0)|(sz<=z3_idx)) == z3.sat:
     print(f"idx={idx.src[1].render(simplify=False)}")
     print(f"mask & gate={mask.render(simplify=False)}")
diff --git a/tinygrad/viz/serve.py b/tinygrad/viz/serve.py
index 196f89c8bb..98fea4bc71 100755
--- a/tinygrad/viz/serve.py
+++ b/tinygrad/viz/serve.py
@@ -80,7 +80,7 @@ def uop_to_json(x:UOp) -> dict[int, dict]:
       if u.op not in {Ops.VIEW, Ops.BUFFER, Ops.KERNEL, Ops.ASSIGN, Ops.COPY, Ops.SINK, *GroupOp.Buffer} and u.st is not None:
         label += f"\n{shape_to_str(u.shape)}"
       elif len(rngs:=u.ranges):
-        label += f"\n({','.join(sorted([colored(str(x.arg[0]), axis_colors[x.arg[1]]) for x in rngs]))})"
+        label += f"\n({','.join([colored(str(x.arg[0]), axis_colors[x.arg[1]]) for x in sorted(rngs, key=lambda x: x.arg[0])])})"
     except Exception:
       label += "\n<ISSUE GETTING LABEL>"
     if (ref:=ref_map.get(u.arg.ast) if u.op is Ops.KERNEL else None) is not None: label += f"\ncodegen@{ctxs[ref]['name']}"