diff --git a/tinygrad/codegen/kernel.py b/tinygrad/codegen/kernel.py
index cc3b85dfd4..b4357b9cf3 100644
--- a/tinygrad/codegen/kernel.py
+++ b/tinygrad/codegen/kernel.py
@@ -777,10 +777,8 @@ class Kernel:
 # the living definition of intermediate UOps
 
 def _assert_valid_uop(uop:UOp, st:ShapeTracker, sts:Dict[UOp, ShapeTracker]) -> None:
-  if uop in sts: return
+  if not uop.has_st or uop in sts: return
   op, _, src, arg = uop.op, uop.dtype, uop.src, uop.arg
-  # NOTE: UOps.DEFINE_GLOBAL and UOps.DEFINE_LOCAL don't have shape
-  if op in {UOps.DEFINE_LOCAL, UOps.DEFINE_GLOBAL}: return
   # restore globals from the two stage reduce
   if op is UOps.LOAD and src[0].op is UOps.DEFINE_LOCAL:
     _assert_valid_uop(local_reduce:=src[2].src[2], uop.st_arg, sts)
@@ -794,9 +792,9 @@ def _assert_valid_uop(uop:UOp, st:ShapeTracker, sts:Dict[UOp, ShapeTracker]) ->
     assert op in {UOps.SHAPETRACKER, UOps.SWIZZLE, UOps.ALU, UOps.CAST, UOps.BITCAST, *BUFFER_UOPS}, f"bad UOp in intermediate uops {uop}"
     # movementops are pushed to the edges with SHAPETRACKER
     # elementwise inherits shape
-    st = arg if op is UOps.SHAPETRACKER else sts[src[uop.st_loc if op in BUFFER_UOPS else -1]]
-    for x in (src[1:] if op in BUFFER_UOPS else src):
-      if sts[x].shape != st.shape:
+    st = arg if op is UOps.SHAPETRACKER else sts[src[uop.st_loc if op in BUFFER_UOPS else 0]]
+    for x in src:
+      if x.has_st and sts[x].shape != st.shape:
         if prod(sts[x].shape) == prod(st.shape): raise AssertionError(f"found implicit reshape {x.op} {op} {sts[x].shape} != {st.shape}")
         raise AssertionError(f"found implicit expand {x.op} {sts[x].shape} != {op} {st.shape} {prod(sts[x].shape)} != {prod(st.shape)}")
   sts[uop] = st
diff --git a/tinygrad/ops.py b/tinygrad/ops.py
index ddc4442125..f013fa7f27 100644
--- a/tinygrad/ops.py
+++ b/tinygrad/ops.py
@@ -143,14 +143,16 @@ class UOp(MathTrait):
     self.op, self.dtype, self.src, self.arg = op, dtype, src, arg
   def replace(self, op: Optional[UOps]=None, dtype:Optional[DType]=None, src: Optional[Tuple[UOp,...]]=None, arg:Any=None):
     return UOp(op or self.op, dtype or self.dtype, self.src if src is None else src, self.arg if arg is None else arg)
+  @property
+  def has_st(self) -> bool: return self.op not in {UOps.DEFINE_LOCAL, UOps.DEFINE_GLOBAL}
   @functools.cached_property
   def st(self) -> Optional[ShapeTracker]:
-    from tinygrad.shape.shapetracker import ShapeTracker
-    if self.op in {UOps.DEFINE_LOCAL, UOps.DEFINE_GLOBAL}: return None
+    if not self.has_st: return None
     if self.op in BUFFER_UOPS: return self.st_arg
     if self.op in {UOps.SHAPETRACKER, UOps.SWIZZLE}: return self.arg
     src_sts = [x.st for x in self.src if x.st is not None]
     assert all_same([x.shape for x in src_sts]), f"UOp parents must have the same shape {self} {[x.shape for x in src_sts]}"
+    from tinygrad.shape.shapetracker import ShapeTracker
     return ShapeTracker.from_shape(src_sts[0].reduce(self.arg[1])) if self.op is UOps.REDUCE_AXIS else src_sts[0]
   @functools.cached_property
   def cmp_tuple(self) -> Tuple[int, Any, Optional[DType], Tuple[UOp, ...]]: