diff --git a/CHANGELOG.md b/CHANGELOG.md
index 84f25baba..b2ca9ac11 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-auth/#history
 
+### [1.14.3](https://www.github.com/googleapis/google-auth-library-python/compare/v1.14.2...v1.14.3) (2020-05-11)
+
+
+### Bug Fixes
+
+* catch exceptions.RefreshError ([#508](https://www.github.com/googleapis/google-auth-library-python/issues/508)) ([3d672e9](https://www.github.com/googleapis/google-auth-library-python/commit/3d672e9cddd9e8c4946290ab9f90ca9009b8be69))
+
 ### [1.14.2](https://www.github.com/googleapis/google-auth-library-python/compare/v1.14.1...v1.14.2) (2020-05-07)
 
 
diff --git a/google/oauth2/id_token.py b/google/oauth2/id_token.py
index f559c6c39..e78add417 100644
--- a/google/oauth2/id_token.py
+++ b/google/oauth2/id_token.py
@@ -212,7 +212,7 @@ def fetch_id_token(request, audience):
         )
         credentials.refresh(request)
         return credentials.token
-    except (ImportError, exceptions.TransportError):
+    except (ImportError, exceptions.TransportError, exceptions.RefreshError):
         pass
 
     # 2. Try to use service account credentials to get ID token.
diff --git a/setup.py b/setup.py
index 83075ecfa..2835f886b 100644
--- a/setup.py
+++ b/setup.py
@@ -30,7 +30,7 @@
 with io.open("README.rst", "r") as fh:
     long_description = fh.read()
 
-version = "1.14.2"
+version = "1.14.3"
 
 setup(
     name="google-auth",
diff --git a/tests/transport/test_requests.py b/tests/transport/test_requests.py
index d24b6f644..ed388d479 100644
--- a/tests/transport/test_requests.py
+++ b/tests/transport/test_requests.py
@@ -268,7 +268,9 @@ def test_request_refresh(self):
         assert adapter.requests[1].headers["authorization"] == "token1"
 
     def test_request_max_allowed_time_timeout_error(self, frozen_time):
-        tick_one_second = functools.partial(frozen_time.tick, delta=1.0)
+        tick_one_second = functools.partial(
+            frozen_time.tick, delta=datetime.timedelta(seconds=1.0)
+        )
 
         credentials = mock.Mock(
             wraps=TimeTickCredentialsStub(time_tick=tick_one_second)
@@ -286,7 +288,9 @@ def test_request_max_allowed_time_timeout_error(self, frozen_time):
             authed_session.request("GET", self.TEST_URL, max_allowed_time=0.9)
 
     def test_request_max_allowed_time_w_transport_timeout_no_error(self, frozen_time):
-        tick_one_second = functools.partial(frozen_time.tick, delta=1.0)
+        tick_one_second = functools.partial(
+            frozen_time.tick, delta=datetime.timedelta(seconds=1.0)
+        )
 
         credentials = mock.Mock(
             wraps=TimeTickCredentialsStub(time_tick=tick_one_second)
@@ -308,7 +312,9 @@ def test_request_max_allowed_time_w_transport_timeout_no_error(self, frozen_time
         authed_session.request("GET", self.TEST_URL, timeout=0.5, max_allowed_time=3.1)
 
     def test_request_max_allowed_time_w_refresh_timeout_no_error(self, frozen_time):
-        tick_one_second = functools.partial(frozen_time.tick, delta=1.0)
+        tick_one_second = functools.partial(
+            frozen_time.tick, delta=datetime.timedelta(seconds=1.0)
+        )
 
         credentials = mock.Mock(
             wraps=TimeTickCredentialsStub(time_tick=tick_one_second)
@@ -333,7 +339,9 @@ def test_request_max_allowed_time_w_refresh_timeout_no_error(self, frozen_time):
         authed_session.request("GET", self.TEST_URL, timeout=60, max_allowed_time=3.1)
 
     def test_request_timeout_w_refresh_timeout_timeout_error(self, frozen_time):
-        tick_one_second = functools.partial(frozen_time.tick, delta=1.0)
+        tick_one_second = functools.partial(
+            frozen_time.tick, delta=datetime.timedelta(seconds=1.0)
+        )
 
         credentials = mock.Mock(
             wraps=TimeTickCredentialsStub(time_tick=tick_one_second)