diff --git a/deploy/memory-pilot/build.sh b/deploy/memory-pilot/build.sh
index 17901ed2da7..79a3b7038c5 100755
--- a/deploy/memory-pilot/build.sh
+++ b/deploy/memory-pilot/build.sh
@@ -1,5 +1,9 @@
 #!/usr/bin/env bash
 set -euo pipefail
+# Render's preinstalled Rust toolchain directory is read-only. Maturin needs
+# writable homes to install the repository's pinned toolchain during uv sync.
+export RUSTUP_HOME="$PWD/.memory-pilot-rustup"
+export CARGO_HOME="$PWD/.memory-pilot-cargo"
 python -m pip install uv==0.11.7
 export UV_PROJECT_ENVIRONMENT="$PWD/.memory-pilot-venv"
 uv sync --frozen --extra proxy --no-default-groups