diff --git a/test/unit/test_device.py b/test/unit/test_device.py
index 7d80b7c497..e0ffe6c6ea 100644
--- a/test/unit/test_device.py
+++ b/test/unit/test_device.py
@@ -8,18 +8,17 @@ from tinygrad.helpers import diskcache_get, diskcache_put, getenv
 
 class TestDevice(unittest.TestCase):
   def test_canonicalize(self):
-    assert Device.canonicalize(None) == Device.DEFAULT
-    assert Device.canonicalize("CPU") == "CPU"
-    assert Device.canonicalize("cpu") == "CPU"
-    assert Device.canonicalize("GPU") == "GPU"
-    assert Device.canonicalize("GPU:0") == "GPU"
-    assert Device.canonicalize("gpu:0") == "GPU"
-    assert Device.canonicalize("GPU:1") == "GPU:1"
-    assert Device.canonicalize("gpu:1") == "GPU:1"
-    assert Device.canonicalize("GPU:2") == "GPU:2"
-    assert Device.canonicalize("disk:/dev/shm/test") == "DISK:/dev/shm/test"
-    # TODO: fix this
-    # assert Device.canonicalize("disk:000.txt") == "DISK:000.txt"
+    self.assertEqual(Device.canonicalize(None), Device.DEFAULT)
+    self.assertEqual(Device.canonicalize("CPU"), "CPU")
+    self.assertEqual(Device.canonicalize("cpu"), "CPU")
+    self.assertEqual(Device.canonicalize("GPU"), "GPU")
+    self.assertEqual(Device.canonicalize("GPU:0"), "GPU")
+    self.assertEqual(Device.canonicalize("gpu:0"), "GPU")
+    self.assertEqual(Device.canonicalize("GPU:1"), "GPU:1")
+    self.assertEqual(Device.canonicalize("gpu:1"), "GPU:1")
+    self.assertEqual(Device.canonicalize("GPU:2"), "GPU:2")
+    self.assertEqual(Device.canonicalize("disk:/dev/shm/test"), "DISK:/dev/shm/test")
+    self.assertEqual(Device.canonicalize("disk:000.txt"), "DISK:000.txt")
 
   def test_getitem_not_exist(self):
     with self.assertRaises(ModuleNotFoundError):
@@ -34,15 +33,15 @@ class TestCompiler(unittest.TestCase):
     diskcache_put("key", "123", None) # clear cache
     getenv.cache_clear()
     with patch.dict(os.environ, {"DISABLE_COMPILER_CACHE": "0"}, clear=True):
-      assert MockCompiler("key").compile_cached("123") == str.encode("123")
-      assert diskcache_get("key", "123") == str.encode("123")
+      self.assertEqual(MockCompiler("key").compile_cached("123"), str.encode("123"))
+      self.assertEqual(diskcache_get("key", "123"), str.encode("123"))
 
   def test_compile_cached_disabled(self):
     diskcache_put("disabled_key", "123", None) # clear cache
     getenv.cache_clear()
     with patch.dict(os.environ, {"DISABLE_COMPILER_CACHE": "1"}, clear=True):
-      assert MockCompiler("disabled_key").compile_cached("123") == str.encode("123")
-      assert diskcache_get("disabled_key", "123") is None
+      self.assertEqual(MockCompiler("disabled_key").compile_cached("123"), str.encode("123"))
+      self.assertIsNone(diskcache_get("disabled_key", "123"))
 
   def test_device_compile(self):
     getenv.cache_clear()
diff --git a/tinygrad/device.py b/tinygrad/device.py
index 19771e2002..6d68785bc6 100644
--- a/tinygrad/device.py
+++ b/tinygrad/device.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 from dataclasses import dataclass, replace
 from collections import defaultdict
 from typing import Optional, Dict, Tuple, Any, Iterator
-import multiprocessing, importlib, inspect, functools, pathlib, os, ctypes, contextlib, sys
+import multiprocessing, importlib, inspect, functools, pathlib, os, ctypes, contextlib, sys, re
 from tinygrad.helpers import CI, OSX, getenv, diskcache_get, diskcache_put, DEBUG, GlobalCounters, flat_mv, from_mv
 from tinygrad.dtype import DType, ImageDType, PtrDType, dtypes
 from tinygrad.renderer import Renderer
@@ -14,7 +14,7 @@ class _Device:
   def __init__(self) -> None:
     self._devices = [x.stem[len("ops_"):].upper() for x in (pathlib.Path(__file__).parent/"runtime").iterdir() if x.stem.startswith("ops_")]
   @functools.lru_cache(maxsize=None)  # this class is a singleton, pylint: disable=method-cache-max-size-none
-  def _canonicalize(self, device:str) -> str: return ((d:=device.split(":", 1)[0].upper()) + device[len(d):]).replace(":0", "")
+  def _canonicalize(self, device:str) -> str: return re.sub(r":0$", "", (d:=device.split(":", 1)[0].upper()) + device[len(d):])
   # NOTE: you can't cache canonicalize in case Device.DEFAULT changes
   def canonicalize(self, device:Optional[str]) -> str: return self._canonicalize(device) if device is not None else Device.DEFAULT
   def __getitem__(self, ix:str) -> Compiled: return self.__get_canonicalized_item(self.canonicalize(ix))