diff --git a/ably/http/http.py b/ably/http/http.py
index e47ffb8f..6a5a4f71 100644
--- a/ably/http/http.py
+++ b/ably/http/http.py
@@ -146,7 +146,8 @@ def get_rest_hosts(self):
         if host is None:
             return hosts
 
-        if time.time() > self.__host_expires:
+        # unstore saved fallback host after fallbackRetryTimeout (RSC15f)
+        if self.__host_expires is not None and time.time() > self.__host_expires:
             self.__host = None
             self.__host_expires = None
             return hosts
diff --git a/test/unit/http_test.py b/test/unit/http_test.py
new file mode 100644
index 00000000..5bc50a63
--- /dev/null
+++ b/test/unit/http_test.py
@@ -0,0 +1,7 @@
+from ably import AblyRest
+
+
+def test_http_get_rest_hosts_does_not_fail_when_fallback_realtime_host_is_set():
+    ably = AblyRest(token="foo")
+    ably.options.fallback_realtime_host = 'fake-host.ably.io'
+    assert ably.http.get_rest_hosts()