diff --git a/stacks/chatterbox/.env.example b/stacks/chatterbox/.env.example
index 93cfef9..7c217a4 100644
--- a/stacks/chatterbox/.env.example
+++ b/stacks/chatterbox/.env.example
@@ -3,9 +3,11 @@
 
 # ── build pin ────────────────────────────────────────────────────────
 # SHA of devnen/Chatterbox-TTS-Server. Bump + rebuild when you want
-# upstream wrapper updates. Pin a SHA — the wrapper has no tagged
-# releases yet.
-CHATTERBOX_SHA=main
+# upstream wrapper updates. Use the FULL 40-char SHA — docker buildx's
+# git source resolver doesn't accept short hashes. Pinning to a SHA
+# (rather than `main`) protects against upstream churn — the previous
+# `main` value broke when devnen restructured docker/ paths in repo.
+CHATTERBOX_SHA=68213e75c248f4f4bbd185f7c20ec02722fdc79b
 
 # Local image tag — bump when you change build context to force a
 # fresh layer build.
diff --git a/stacks/chatterbox/compose.yaml b/stacks/chatterbox/compose.yaml
index ac89496..3527eb3 100644
--- a/stacks/chatterbox/compose.yaml
+++ b/stacks/chatterbox/compose.yaml
@@ -24,7 +24,12 @@ services:
     image: local/chatterbox:${CHATTERBOX_TAG}
     build:
       context: https://github.com/devnen/Chatterbox-TTS-Server.git#${CHATTERBOX_SHA}
-      dockerfile: docker/Dockerfile.gpu
+      # Upstream moved Dockerfiles from docker/ to repo root and renamed
+      # them by CUDA version (Dockerfile.cu128, .cpu, .rocm). The old
+      # `docker/Dockerfile.gpu` is gone. cu128 is the GPU build for
+      # CUDA 12.8 — fits irv-ml1's 595.58.03 driver (CUDA 13.2 capable,
+      # backward-compatible to 12.8 toolkit-built images).
+      dockerfile: Dockerfile.cu128
     container_name: chatterbox
     restart: unless-stopped
     runtime: nvidia
diff --git a/stacks/vibevoice/.env.example b/stacks/vibevoice/.env.example
index 8f0d3ae..c7ab299 100644
--- a/stacks/vibevoice/.env.example
+++ b/stacks/vibevoice/.env.example
@@ -4,8 +4,10 @@
 # ── build pin ────────────────────────────────────────────────────────
 # SHA of groxaxo/VibeVoice-FastAPI1 (a more current fork of
 # ncoder-ai/VibeVoice-FastAPI). Bump + rebuild when you want upstream
-# wrapper updates.
-VIBEVOICE_SHA=7614c469a145
+# wrapper updates. Use the FULL 40-char SHA — docker buildx's git
+# source resolver doesn't accept short hashes, even when they're
+# unambiguous (it errors with "repository does not contain ref X").
+VIBEVOICE_SHA=7614c469a145dafc30b1fd5f6a6046ea831dbd6a
 
 # Local image tag — bump when you change build context to force a
 # fresh layer build.