--- a/python/mozbuild/mozbuild/base.py
+++ b/python/mozbuild/mozbuild/base.py
@@ -85,17 +85,16 @@ class MozbuildObject(ProcessExecutionMix
         self.settings = settings
 
         self.populate_logger()
         self.log_manager = log_manager
 
         self._make = None
         self._topobjdir = mozpath.normsep(topobjdir) if topobjdir else topobjdir
         self._mozconfig = mozconfig
-        self._config_guess_output = None
         self._config_environment = None
         self._virtualenv_manager = None
 
     @classmethod
     def from_environment(cls, cwd=None, detect_virtualenv_mozinfo=True):
         """Create a MozbuildObject by detecting the proper one from the env.
 
         This examines environment state like the current working directory and
@@ -438,24 +437,16 @@ class MozbuildObject(ProcessExecutionMix
                 params = FLASHWINDOW(sizeof(FLASHWINDOW),
                                     console,
                                     FLASHW_CAPTION | FLASHW_TRAY | FLASHW_TIMERNOFG, 3, 0)
                 FlashWindowEx(params)
         except Exception as e:
             self.log(logging.WARNING, 'notifier-failed', {'error':
                 e.message}, 'Notification center failed: {error}')
 
-    @property
-    def _config_guess(self):
-        if self._config_guess_output is None:
-            self._config_guess_output = MozbuildObject.resolve_config_guess(
-                self.mozconfig, self.topsrcdir)
-
-        return self._config_guess_output
-
     def _ensure_objdir_exists(self):
         if os.path.isdir(self.statedir):
             return
 
         os.makedirs(self.statedir)
 
     def _ensure_state_subdir_exists(self, subdir):
         path = os.path.join(self.statedir, subdir)

--- a/python/mozbuild/mozbuild/test/test_base.py
+++ b/python/mozbuild/mozbuild/test/test_base.py
@@ -55,17 +55,19 @@ class TestMozbuildObject(unittest.TestCa
     def test_objdir_config_guess(self):
         base = self.get_base()
 
         with NamedTemporaryFile() as mozconfig:
             os.environ[b'MOZCONFIG'] = mozconfig.name
 
             self.assertIsNotNone(base.topobjdir)
             self.assertEqual(len(base.topobjdir.split()), 1)
-            self.assertTrue(base.topobjdir.endswith(base._config_guess))
+            config_guess = MozbuildObject.resolve_config_guess(base.mozconfig,
+                                                               base.topsrcdir)
+            self.assertTrue(base.topobjdir.endswith(config_guess))
             self.assertTrue(os.path.isabs(base.topobjdir))
             self.assertTrue(base.topobjdir.startswith(base.topsrcdir))
 
     def test_objdir_trailing_slash(self):
         """Trailing slashes in topobjdir should be removed."""
         base = self.get_base()
 
         with NamedTemporaryFile() as mozconfig:
@@ -293,25 +295,16 @@ class TestMozbuildObject(unittest.TestCa
                     'Ambiguous object directory detected.'))
             finally:
                 sys.stdout = stdout
 
         finally:
             os.chdir(self._old_cwd)
             shutil.rmtree(d)
 
-    def test_config_guess(self):
-        # It's difficult to test for exact values from the output of
-        # config.guess because they vary depending on platform.
-        base = self.get_base()
-        result = base._config_guess
-
-        self.assertIsNotNone(result)
-        self.assertGreater(len(result), 0)
-
     def test_config_environment(self):
         base = self.get_base(topobjdir=topobjdir)
 
         ce = base.config_environment
         self.assertIsInstance(ce, ConfigEnvironment)
 
         self.assertEqual(base.defines, ce.defines)
         self.assertEqual(base.substs, ce.substs)