diff --git a/.cargo/config.toml b/.cargo/config.toml
new file mode 100644
index 000000000..f832ab7e6
--- /dev/null
+++ b/.cargo/config.toml
@@ -0,0 +1,11 @@
+# Cargo environment for the workspace.
+#
+# audiopus_sys 0.2.2 builds its vendored Opus via the `cmake` crate, and the
+# bundled opus CMakeLists still declares `cmake_minimum_required(VERSION 3.1)`.
+# CMake 4.0 removed compatibility with < 3.5, so any dev host with a modern
+# cmake fails `cargo check`/`cargo clippy` on pi-voice with
+# "Compatibility with CMake < 3.5 has been removed from CMake." The bazel build
+# already sets this override for the same crate (see the audiopus_sys
+# annotation in MODULE.bazel); mirror it here so the cargo path works too.
+[env]
+CMAKE_POLICY_VERSION_MINIMUM = "3.5"