diff --git a/.github/configurations/vllm-tensorizer.yml b/.github/configurations/vllm-tensorizer.yml
index a50ccd32..da1fedf0 100644
--- a/.github/configurations/vllm-tensorizer.yml
+++ b/.github/configurations/vllm-tensorizer.yml
@@ -1,5 +1,5 @@
 vllm-commit:
-  - 'v0.19.0'
+  - 'v0.19.1'
 flashinfer-commit:
   - 'v0.6.6'
 lmcache-commit:
diff --git a/vllm-tensorizer/Dockerfile b/vllm-tensorizer/Dockerfile
index f8669b34..ccb036bc 100644
--- a/vllm-tensorizer/Dockerfile
+++ b/vllm-tensorizer/Dockerfile
@@ -293,8 +293,9 @@ ARG TARGETPLATFORM
 # Ray was removed as a default dependancy by vllm in v18, but it is still required
 # for the multi-node setup.
 
-# Gemma 4 needs transformers > 5.5.0, but is packaged with 4 in vllm 19.
-# We must explicitly update it until vLLM updates their dependency.
+# * Gemma 4 needs transformers > 5.5.0
+# * Kimi K2.5 tool-call scramble fixed in transformers 5.5.4 (huggingface/transformers#45359)
+# * Kimi K2.5 registry-subprocess SIGSEGV on GB200 with nixl-cu12 1.0.1 (vllm-project/vllm#40642) — pin both to 1.0.0
 
 RUN if [ "$TARGETPLATFORM" = "linux/arm64" ]; then \
       BITSANDBYTES_VER='0.42.0'; \
@@ -303,7 +304,9 @@ RUN if [ "$TARGETPLATFORM" = "linux/arm64" ]; then \
     fi && \
     python3 -m pip install --no-cache-dir \
       accelerate hf_transfer 'modelscope!=1.15.0' "bitsandbytes>=${BITSANDBYTES_VER:?}" 'timm>=1.0.17' \
-      'runai-model-streamer[s3,gcs]>=0.15.3' "ray[cgraph]>=2.48.0" "transformers>=5.5.0" -c /tmp/constraints.txt && \
+      'runai-model-streamer[s3,gcs]>=0.15.3' "ray[cgraph]>=2.48.0" \
+      'transformers==5.5.4' 'nixl==1.0.0' 'nixl-cu12==1.0.0' \
+      -c /tmp/constraints.txt && \
     rm /tmp/constraints.txt
 
 EXPOSE 8080