diff --git a/Dockerfile.ubi b/Dockerfile.ubi
index 230966ffc74a..df2e3bedc174 100644
--- a/Dockerfile.ubi
+++ b/Dockerfile.ubi
@@ -180,6 +180,10 @@ RUN --mount=type=cache,target=/root/.cache/pip \
     --mount=type=cache,target=/root/.cache/uv \
     uv pip install https://github.com/flashinfer-ai/flashinfer/releases/download/v0.1.2/flashinfer-0.1.2+cu121torch2.4-cp311-cp311-linux_x86_64.whl
 
+# Install peft for prompt adapter support
+RUN --mount=type=cache,target=/root/.cache/pip \
+    uv pip install peft==0.12.0
+
 ENV HF_HUB_OFFLINE=1 \
     HOME=/home/vllm \
     # Allow requested max length to exceed what is extracted from the