diff --git a/tinygrad/frontend/onnx.py b/tinygrad/frontend/onnx.py
index bcead3994d..d8a3cade76 100644
--- a/tinygrad/frontend/onnx.py
+++ b/tinygrad/frontend/onnx.py
@@ -5,7 +5,7 @@ from io import BufferedReader
 from tinygrad.nn.state import TensorIO
 from tinygrad.tensor import Tensor, _broadcast_shape, ReductionStr
 from tinygrad.helpers import getenv, DEBUG, all_same, prod, flatten, make_tuple, argsort, is_numpy_ndarray, get_single_element, polyN
-from tinygrad.dtype import DType, ConstType, dtypes, _from_np_dtype
+from tinygrad.dtype import DType, ConstType, dtypes, _from_np_dtype, truncate
 from tinygrad.device import is_dtype_supported, Device
 
 # ***** protobuf definitions ******
@@ -105,9 +105,7 @@ class PBBufferedReader(BufferedReader):
   def read_bytes(self) -> Tensor: return self.read_delimited(use_tensor=True)
   def read_float(self) -> float: return struct.unpack("<f", self.read(4))[0]
   def read_packed_floats(self) -> Tensor: return self.read_delimited(use_tensor=True)
-  def read_int64(self) -> int:
-    val = self.decode_varint()
-    return val - 2**64 if val & (1 << 63) else val
+  def read_int64(self) -> int: return truncate[dtypes.int64](self.decode_varint())
   def read_packed_int64s(self) -> list[int]:
     total_bytes_len = self.decode_varint()
     old_pos = self.tell()