diff --git a/homeassistant/components/sensor/rest.py b/homeassistant/components/sensor/rest.py
index c295dcf16dc..74bfaa38f02 100644
--- a/homeassistant/components/sensor/rest.py
+++ b/homeassistant/components/sensor/rest.py
@@ -130,18 +130,20 @@ class RestSensor(Entity):
 
         if self._json_attrs:
             self._attributes = {}
-            try:
-                json_dict = json.loads(value)
-                if isinstance(json_dict, dict):
-                    attrs = {k: json_dict[k] for k in self._json_attrs
-                             if k in json_dict}
-                    self._attributes = attrs
-                else:
-                    _LOGGER.warning("JSON result was not a dictionary")
-            except ValueError:
-                _LOGGER.warning("REST result could not be parsed as JSON")
-                _LOGGER.debug("Erroneous JSON: %s", value)
-
+            if value:
+                try:
+                    json_dict = json.loads(value)
+                    if isinstance(json_dict, dict):
+                        attrs = {k: json_dict[k] for k in self._json_attrs
+                                 if k in json_dict}
+                        self._attributes = attrs
+                    else:
+                        _LOGGER.warning("JSON result was not a dictionary")
+                except ValueError:
+                    _LOGGER.warning("REST result could not be parsed as JSON")
+                    _LOGGER.debug("Erroneous JSON: %s", value)
+            else:
+                _LOGGER.warning("Empty reply found when expecting JSON data")
         if value is None:
             value = STATE_UNKNOWN
         elif self._value_template is not None:
diff --git a/tests/components/sensor/test_rest.py b/tests/components/sensor/test_rest.py
index eddab8caf4d..f2362867979 100644
--- a/tests/components/sensor/test_rest.py
+++ b/tests/components/sensor/test_rest.py
@@ -207,6 +207,18 @@ class TestRestSensor(unittest.TestCase):
         self.assertEqual('some_json_value',
                          self.sensor.device_state_attributes['key'])
 
+    @patch('homeassistant.components.sensor.rest._LOGGER')
+    def test_update_with_json_attrs_no_data(self, mock_logger):
+        """Test attributes when no JSON result fetched."""
+        self.rest.update = Mock('rest.RestData.update',
+                                side_effect=self.update_side_effect(None))
+        self.sensor = rest.RestSensor(self.hass, self.rest, self.name,
+                                      self.unit_of_measurement, None, ['key'],
+                                      self.force_update)
+        self.sensor.update()
+        self.assertEqual({}, self.sensor.device_state_attributes)
+        self.assertTrue(mock_logger.warning.called)
+
     @patch('homeassistant.components.sensor.rest._LOGGER')
     def test_update_with_json_attrs_not_dict(self, mock_logger):
         """Test attributes get extracted from a JSON result."""