diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c6e92bd..225ecbbe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,7 +16,7 @@
 * Upgrading to Realm Object Server 2.0.0-rc.4.
 * OpenSSL for Android is distributed in a separate package, and the build system needed updates to accommendate this.
 * Added `-fvisibility=hidden` to Android builds (reduces size of `.so` file).
-
+* Add `Session._overrideServer` to force an existing session to connect to a different server.
 
 2.0.0-rc19 Release notes (2017-10-7)
 =============================================================
diff --git a/dependencies.list b/dependencies.list
index 14312953..eb7f65aa 100644
--- a/dependencies.list
+++ b/dependencies.list
@@ -1,5 +1,5 @@
 PACKAGE_NAME=realm-js
 VERSION=2.0.0-rc20
-REALM_CORE_VERSION=4.0.1
-REALM_SYNC_VERSION=2.0.0-rc28
+REALM_CORE_VERSION=4.0.2
+REALM_SYNC_VERSION=2.0.1
 REALM_OBJECT_SERVER_VERSION=2.0.0-rc.4
diff --git a/src/js_sync.hpp b/src/js_sync.hpp
index 8e0310fd..1e6961c5 100644
--- a/src/js_sync.hpp
+++ b/src/js_sync.hpp
@@ -179,6 +179,7 @@ class SessionClass : public ClassDefinition<T, WeakSession> {
     using Object = js::Object<T>;
     using Value = js::Value<T>;
     using ReturnValue = js::ReturnValue<T>;
+    using Arguments = js::Arguments<T>;
 
 public:
     std::string const name = "Session";
@@ -196,6 +197,8 @@ public:
     static void add_progress_notification(ContextType ctx, FunctionType, ObjectType this_object, size_t argc, const ValueType arguments[], ReturnValue &);
     static void remove_progress_notification(ContextType ctx, FunctionType, ObjectType this_object, size_t argc, const ValueType arguments[], ReturnValue &);
 
+    static void override_server(ContextType ctx, ObjectType this_object, Arguments args, ReturnValue&);
+
     PropertyMap<T> const properties = {
         {"config", {wrap<get_config>, nullptr}},
         {"user", {wrap<get_user>, nullptr}},
@@ -206,6 +209,7 @@ public:
     MethodMap<T> const methods = {
         {"_simulateError", wrap<simulate_error>},
         {"_refreshAccessToken", wrap<refresh_access_token>},
+        {"_overrideServer", wrap<override_server>},
         {"addProgressNotification", wrap<add_progress_notification>},
         {"removeProgressNotification", wrap<remove_progress_notification>},
     };
@@ -511,6 +515,23 @@ void SessionClass<T>::remove_progress_notification(ContextType ctx, FunctionType
     }
 }
 
+template<typename T>
+void SessionClass<T>::override_server(ContextType ctx, ObjectType this_object, Arguments args, ReturnValue&) {
+    args.validate_count(2);
+
+    std::string address = Value::validated_to_string(ctx, args[0], "address");
+    double port = Value::validated_to_number(ctx, args[1], "port");
+    if (port < 1 || port > 65535 || uint16_t(port) != port) {
+        std::ostringstream message;
+        message << "Invalid port number. Expected an integer in the range 1-65,535, got '" << port << "'";
+        throw std::invalid_argument(message.str());
+    }
+
+    if (auto session = get_internal<T, SessionClass<T>>(this_object)->lock()) {
+        session->override_server(std::move(address), uint16_t(port));
+    }
+}
+
 template<typename T>
 class SyncClass : public ClassDefinition<T, void*> {
     using GlobalContextType = typename T::GlobalContext;
diff --git a/src/object-store b/src/object-store
index 0b1a2ad7..054b5c09 160000
--- a/src/object-store
+++ b/src/object-store
@@ -1 +1 @@
-Subproject commit 0b1a2ad7bc1269d4399785240a525e587cd9ddda
+Subproject commit 054b5c09711555949f0e281a3bc195d4813b066e