diff --git a/test/null/test_viz.py b/test/null/test_viz.py
index b02a6ef675..a8d3369351 100644
--- a/test/null/test_viz.py
+++ b/test/null/test_viz.py
@@ -222,6 +222,16 @@ class TestViz(unittest.TestCase):
       graph_rewrite(a + 4, TrackedPatternMatcher(_substitute.patterns), {a:a+1}, walk=True)
     list(viz.get_details(0, 0))
 
+  def test_enter_calls_rewrite(self):
+    pm = PatternMatcher([(UPat(Ops.CONST, arg=3, name="x"), lambda x: x.replace(arg=4))])
+    with save_viz() as viz:
+      inner = UOp.const(dtypes.int, 3)
+      func = UOp(Ops.FUNCTION, src=(UOp(Ops.SINK, src=(inner,)),))
+      call = UOp(Ops.CALL, src=(func,))
+      graph_rewrite(call, TrackedPatternMatcher(pm.patterns), enter_calls=True)
+    details = list(viz.get_details(0, 0))
+    self.assertTrue(details[-1]["change"], "viz replay should detect change inside CALL")
+
   def test_const_node_visibility(self):
     with save_viz() as viz:
       a = UOp.variable("a", 0, 10, dtype=dtypes.int)
diff --git a/tinygrad/uop/ops.py b/tinygrad/uop/ops.py
index d6f38cbb1e..4ef821d952 100644
--- a/tinygrad/uop/ops.py
+++ b/tinygrad/uop/ops.py
@@ -440,12 +440,12 @@ class UOp(RandMixin, metaclass=UOpMetaClass):
   def __bool__(self): return self._eval((dtypes.bool,), bool)
   def __int__(self): return self._eval(dtypes.ints, int)
   def __float__(self): return float(self._eval(dtypes.floats, float))
-  def substitute(self, dvars:dict[UOp, UOp], name:str|None=None, extra_pm:PatternMatcher|None=None, walk:bool=False):
+  def substitute(self, dvars:dict[UOp, UOp], name:str|None=None, extra_pm:PatternMatcher|None=None, walk:bool=False, enter_calls:bool=False):
     dvars = {k:v for k,v in dvars.items() if k is not v}
     if len(dvars) == 0: return self
     with Context(TRACK_MATCH_STATS=(0 if name is None else TRACK_MATCH_STATS.value)):
       return graph_rewrite(self, (extra_pm+_substitute) if extra_pm is not None else _substitute, dvars,
-                           bottom_up=True, walk=walk, name=name)
+                           bottom_up=True, walk=walk, enter_calls=enter_calls, name=name)
   # NOTE: this is not called by Tensor slice (Tensor handles UOps directly), but satisfies SupportsIndex for type checking
   def __index__(self): return self.__int__()
 
@@ -1397,6 +1397,7 @@ class TrackedGraphRewrite:
   depth:int                                     # depth if it's a subrewrite
   bottom_up:bool
   walk:bool
+  enter_calls:bool
 
 tracked_keys:list[TracingKey] = []
 tracked_ctxs:list[list[TrackedGraphRewrite]] = []
@@ -1454,7 +1455,7 @@ def profile_matches(fxn:Callable):
       if not tracked_ctxs: add_trace_group(TracingKey(f"default {fxn.__name__}"))
       dest_group = active_group[-1] if active_group else len(tracked_ctxs)-1
       tracked_ctxs[dest_group].append(ctx:=TrackedGraphRewrite(loc, args[0].trace_num, [], name, depth, kwargs.get("bottom_up", False),
-                                                               kwargs.get("walk", False)))
+                                                               kwargs.get("walk", False), kwargs.get("enter_calls", False)))
       active_rewrites.append(ctx)
       with cpu_profile(name, "TINY"):
         ret = fxn(*args, **kwargs)
diff --git a/tinygrad/viz/serve.py b/tinygrad/viz/serve.py
index a1438e56cb..a633cb3823 100755
--- a/tinygrad/viz/serve.py
+++ b/tinygrad/viz/serve.py
@@ -184,7 +184,7 @@ def get_full_rewrite(data:VizData, ctx:TrackedGraphRewrite, depth:int|None=None)
   replaces: dict[UOp, UOp] = {}
   for u0_num,u1_num,upat_loc,dur in tqdm(ctx.matches, disable=not ctx.matches):
     replaces[u0:=_reconstruct(data, u0_num, depth=depth)] = u1 = _reconstruct(data, u1_num, depth=depth)
-    try: new_sink = next_sink.substitute(replaces, walk=ctx.walk)
+    try: new_sink = next_sink.substitute(replaces, walk=ctx.walk, enter_calls=ctx.enter_calls)
     except RuntimeError as e: new_sink = UOp(Ops.NOOP, arg=str(e))
     match_repr = f"# {dur*1e6:.2f} us\n"+printable(upat_loc)
     yield {"graph":(sink_json:=uop_to_json(data, new_sink)), "uop":pystr(new_sink), "change":[id(x) for x in u1.toposort() if id(x) in sink_json],