diff --git a/gtfs-spec b/gtfs-spec
index f09941e..3909a9e 160000
--- a/gtfs-spec
+++ b/gtfs-spec
@@ -1 +1 @@
-Subproject commit f09941e239f0fd48e8ceaeef0195bbe4c632064b
+Subproject commit 3909a9e322c0cc03861a7edaa7fc146961bc8fe9
diff --git a/nodejs/package-lock.json b/nodejs/package-lock.json
index 5f17c6a..d33f069 100644
--- a/nodejs/package-lock.json
+++ b/nodejs/package-lock.json
@@ -1,12 +1,12 @@
 {
     "name": "gtfs-realtime-bindings-transit",
-    "version": "1.8.7",
+    "version": "1.8.8",
     "lockfileVersion": 2,
     "requires": true,
     "packages": {
         "": {
             "name": "gtfs-realtime-bindings-transit",
-            "version": "1.8.7",
+            "version": "1.8.8",
             "dependencies": {
                 "protobufjs": "=7.2.5"
             },
diff --git a/nodejs/types.d.ts b/nodejs/types.d.ts
index 74312c0..50768c9 100644
--- a/nodejs/types.d.ts
+++ b/nodejs/types.d.ts
@@ -1,6 +1,5 @@
 import * as $protobuf from "protobufjs";
 import { Long } from "protobufjs";
-
 /** Properties of a TransitAlertExtension. */
 export interface ITransitAlertExtension {
 
diff --git a/rust/gtfs-spec-no-extensions/gtfs-realtime/proto/gtfs-realtime.proto b/rust/gtfs-spec-no-extensions/gtfs-realtime/proto/gtfs-realtime.proto
index a6884cf..09816b4 100644
--- a/rust/gtfs-spec-no-extensions/gtfs-realtime/proto/gtfs-realtime.proto
+++ b/rust/gtfs-spec-no-extensions/gtfs-realtime/proto/gtfs-realtime.proto
@@ -1279,8 +1279,7 @@ message ReplacementStop {
   // modifications to the spec.
   extensions 1000 to 1999;
 
-  // The following extension IDs are reserved for private use by any organization.
-  extensions 9000 to 9999;
+  optional TransitReplacementStopExtension transit_replacement_stop_extension = 9514;
 }
 
 message TransitModificationExtension {
@@ -1292,4 +1291,11 @@ message TransitModificationExtension {
 
   // Modification to identify that whole modification
   optional string modification_id = 3;
-}
\ No newline at end of file
+}
+
+message TransitReplacementStopExtension {
+  // See `transit-extensions.proto`
+  optional bool no_through_travel = 1;
+  optional string next_shape_id = 2;
+}
+
diff --git a/transit-extensions.proto b/transit-extensions.proto
index 86e8906..40937cc 100644
--- a/transit-extensions.proto
+++ b/transit-extensions.proto
@@ -139,6 +139,29 @@ message TransitModificationExtension {
   optional string modification_id = 3;
 }
 
+message TransitReplacementStopExtension {
+  // Indicates that vehicles will not continue travelling. Riders must disembark
+  // from the vehicle.
+  required bool no_through_travel = 1;
+
+  // If the vehicle is not operating in revenue service beyond this stop, this field
+  // must be populated with a new shape ID for the next segment of stops.
+  required string next_shape_id = 2;
+}
+
+message TransitModifiedTripSelector {
+  optional int32 split_service_segment_index = 1;
+}
+
 extend transit_realtime.TripModifications.Modification {
   optional TransitModificationExtension transit_modification_extension = 9514;
-}
\ No newline at end of file
+}
+
+extend transit_realtime.ReplacementStop {
+  optional TransitReplacementStopExtension transit_replacement_stop_extension = 9514;
+}
+
+extend transit_realtime.TripDescriptor.ModifiedTripSelector {
+  optional TransitModifiedTripSelector transit_modified_trip_selector_extension = 9514;
+}
+