diff --git a/python/ray/tune/experiment.py b/python/ray/tune/experiment.py
index 81ad29ac9..480aade4b 100644
--- a/python/ray/tune/experiment.py
+++ b/python/ray/tune/experiment.py
@@ -102,9 +102,9 @@ class Experiment(object):
                     "criteria must take exactly 2 parameters.".format(stop))
 
         config = config or {}
-        run_identifier = Experiment._register_if_needed(run)
+        self._run_identifier = Experiment._register_if_needed(run)
         spec = {
-            "run": run_identifier,
+            "run": self._run_identifier,
             "stop": stop,
             "config": config,
             "resources_per_trial": resources_per_trial,
@@ -125,7 +125,7 @@ class Experiment(object):
             if restore else None
         }
 
-        self.name = name or run_identifier
+        self.name = name or self._run_identifier
         self.spec = spec
 
     @classmethod
@@ -202,6 +202,11 @@ class Experiment(object):
         if self.spec["upload_dir"]:
             return os.path.join(self.spec["upload_dir"], self.name)
 
+    @property
+    def run_identifier(self):
+        """Returns a string representing the trainable identifier."""
+        return self._run_identifier
+
 
 def convert_to_experiment_list(experiments):
     """Produces a list of Experiment objects.
diff --git a/python/ray/tune/tune.py b/python/ray/tune/tune.py
index 893d22201..69acbfba8 100644
--- a/python/ray/tune/tune.py
+++ b/python/ray/tune/tune.py
@@ -4,6 +4,7 @@ from __future__ import print_function
 
 import logging
 import time
+import six
 
 from ray.tune.error import TuneError
 from ray.tune.experiment import convert_to_experiment_list, Experiment
@@ -45,6 +46,9 @@ def _make_scheduler(args):
 
 
 def _check_default_resources_override(run_identifier):
+    if not isinstance(run_identifier, six.string_types):
+        # If obscure dtype, assume it is overriden.
+        return True
     trainable_cls = get_trainable_cls(run_identifier)
     return hasattr(trainable_cls, "default_resource_request") and (
         trainable_cls.default_resource_request.__code__ !=
@@ -265,7 +269,7 @@ def run(run_or_experiment,
                       dict) and "gpu" in resources_per_trial:
             # "gpu" is manually set.
             pass
-        elif _check_default_resources_override(run_identifier):
+        elif _check_default_resources_override(experiment.run_identifier):
             # "default_resources" is manually overriden.
             pass
         else: