diff --git a/README.md b/README.md
index 3fe2818..ad64b2c 100644
--- a/README.md
+++ b/README.md
@@ -50,4 +50,11 @@ backend = build_backend("python", classic_config(), seed=1)
 snapshot = backend.snapshot()
 ```
 
+Rust sources live outside the Python package:
+
+```text
+rust/lost-cities-core/
+proto/lost_cities.proto
+```
+
 See [classic port notes](docs/classic-port-notes.md) for the current direction.
diff --git a/docs/classic-port-notes.md b/docs/classic-port-notes.md
index 7247fad..40c739c 100644
--- a/docs/classic-port-notes.md
+++ b/docs/classic-port-notes.md
@@ -30,7 +30,10 @@ src/coolrl_lost_cities/
       fixtures/
       assets/
       docs/
-      rust_core/
+rust/
+  lost-cities-core/
+proto/
+  lost_cities.proto
 ```
 
 Tests should live outside the package, roughly under:
diff --git a/src/coolrl_lost_cities/games/classic/schemas/lost_cities.proto b/proto/lost_cities.proto
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/schemas/lost_cities.proto
rename to proto/lost_cities.proto
diff --git a/pyproject.toml b/pyproject.toml
index a0ba890..716a969 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,10 +39,4 @@ include = ["coolrl_lost_cities*"]
     "assets/*.json",
     "fixtures/*.json",
     "docs/*.md",
-    "schemas/*.proto",
-    "rust_core/Cargo.lock",
-    "rust_core/Cargo.toml",
-    "rust_core/build.rs",
-    "rust_core/src/*.rs",
-    "rust_core/src/bin/*.rs",
 ]
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/Cargo.lock b/rust/lost-cities-core/Cargo.lock
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/Cargo.lock
rename to rust/lost-cities-core/Cargo.lock
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/Cargo.toml b/rust/lost-cities-core/Cargo.toml
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/Cargo.toml
rename to rust/lost-cities-core/Cargo.toml
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/build.rs b/rust/lost-cities-core/build.rs
similarity index 89%
rename from src/coolrl_lost_cities/games/classic/rust_core/build.rs
rename to rust/lost-cities-core/build.rs
index 48b2d3e..09a4673 100644
--- a/src/coolrl_lost_cities/games/classic/rust_core/build.rs
+++ b/rust/lost-cities-core/build.rs
@@ -4,7 +4,7 @@ fn main() {
     let protoc = protoc_bin_vendored::protoc_bin_path().expect("vendored protoc");
     std::env::set_var("PROTOC", protoc);
 
-    let proto_dir = PathBuf::from("../schemas");
+    let proto_dir = PathBuf::from("../../proto");
     let proto_file = proto_dir.join("lost_cities.proto");
 
     println!("cargo:rerun-if-changed={}", proto_file.display());
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/bin/lost_cities_probe.rs b/rust/lost-cities-core/src/bin/lost_cities_probe.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/bin/lost_cities_probe.rs
rename to rust/lost-cities-core/src/bin/lost_cities_probe.rs
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/config.rs b/rust/lost-cities-core/src/config.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/config.rs
rename to rust/lost-cities-core/src/config.rs
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/engine.rs b/rust/lost-cities-core/src/engine.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/engine.rs
rename to rust/lost-cities-core/src/engine.rs
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/error.rs b/rust/lost-cities-core/src/error.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/error.rs
rename to rust/lost-cities-core/src/error.rs
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/lib.rs b/rust/lost-cities-core/src/lib.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/lib.rs
rename to rust/lost-cities-core/src/lib.rs
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/service.rs b/rust/lost-cities-core/src/service.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/service.rs
rename to rust/lost-cities-core/src/service.rs
diff --git a/src/coolrl_lost_cities/games/classic/rust_core/src/state.rs b/rust/lost-cities-core/src/state.rs
similarity index 100%
rename from src/coolrl_lost_cities/games/classic/rust_core/src/state.rs
rename to rust/lost-cities-core/src/state.rs
diff --git a/src/coolrl_lost_cities/games/classic/backends/rust.py b/src/coolrl_lost_cities/games/classic/backends/rust.py
index a2f7ec2..8938f98 100644
--- a/src/coolrl_lost_cities/games/classic/backends/rust.py
+++ b/src/coolrl_lost_cities/games/classic/backends/rust.py
@@ -12,6 +12,7 @@ from ..interfaces import BackendName, Snapshot
 from .common import snapshot_from_trace, snapshot_summary
 
 LOGGER = logging.getLogger("coolrl_lost_cities.games.classic.backends.rust")
+RUST_CORE_DIR = Path(__file__).resolve().parents[5] / "rust" / "lost-cities-core"
 
 
 class RustLostCitiesBackend:
@@ -70,7 +71,6 @@ class RustLostCitiesBackend:
             "steps": [{"action": None}]
             + [{"action": action} for action in self.actions],
         }
-        rust_core = Path(__file__).resolve().parents[1] / "rust_core"
         with tempfile.NamedTemporaryFile("w", suffix=".json", delete=False) as handle:
             json.dump(fixture, handle)
             fixture_path = Path(handle.name)
@@ -86,7 +86,7 @@ class RustLostCitiesBackend:
                     "trace",
                     str(fixture_path),
                 ],
-                cwd=rust_core,
+                cwd=RUST_CORE_DIR,
                 check=True,
                 text=True,
                 capture_output=True,
diff --git a/tests/games/classic/test_rust_parity.py b/tests/games/classic/test_rust_parity.py
index bc6fead..1e7b916 100644
--- a/tests/games/classic/test_rust_parity.py
+++ b/tests/games/classic/test_rust_parity.py
@@ -5,11 +5,11 @@ import subprocess
 
 import coolrl_lost_cities.games.classic as classic
 from coolrl_lost_cities.games.classic.game import GameState, LostCitiesConfig, build_deck
+from coolrl_lost_cities.games.classic.backends.rust import RUST_CORE_DIR
 
 
 LOST_CITIES_DIR = Path(classic.__file__).resolve().parent
 FIXTURE_DIR = LOST_CITIES_DIR / "fixtures"
-RUST_CORE_DIR = LOST_CITIES_DIR / "rust_core"
 
 
 def _run_probe(*args: str) -> dict: