diff --git a/Cargo.lock b/Cargo.lock
index 39a72ac..bbf980b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -611,9 +611,9 @@ checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
 [[package]]
 name = "base64"
-version = "0.23.0"
+version = "0.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b25655df2c3cdd83c5e5b293b88acd880332b2ddadd7c30ac43144fdc0033da9"
+checksum = "ac07cdecf99051d9a5238b80f35af32cdeba5b336e55d957b318b50137e18da5"
 
 [[package]]
 name = "base64-simd"
@@ -784,7 +784,7 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "axum",
- "base64 0.23.0",
+ "base64 0.23.1",
  "bytes",
  "chrono",
  "conduit-anthropic",
@@ -923,7 +923,7 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "axum",
- "base64 0.23.0",
+ "base64 0.23.1",
  "bytes",
  "conduit-core",
  "conduit-http",
@@ -1153,7 +1153,7 @@ dependencies = [
  "conduit-provider",
  "futures-util",
  "hound",
- "ndarray 0.16.1",
+ "ndarray",
  "ort",
  "tokio",
  "tokio-stream",
@@ -1828,6 +1828,12 @@ dependencies = [
  "digest 0.11.3",
 ]
 
+[[package]]
+name = "hmac-sha256"
+version = "1.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec9d92d097f4749b64e8cc33d924d9f40a2d4eb91402b458014b781f5733d60f"
+
 [[package]]
 name = "hound"
 version = "3.5.1"
@@ -1927,7 +1933,7 @@ dependencies = [
  "httpdate",
  "itoa",
  "pin-project-lite",
- "smallvec 1.15.2",
+ "smallvec",
  "tokio",
  "want",
 ]
@@ -2033,7 +2039,7 @@ dependencies = [
  "icu_normalizer_data",
  "icu_properties",
  "icu_provider",
- "smallvec 1.15.2",
+ "smallvec",
  "zerovec",
 ]
 
@@ -2085,7 +2091,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3b0875f23caa03898994f6ddc501886a45c7d3d62d04d2d90788d47be1b1e4de"
 dependencies = [
  "idna_adapter",
- "smallvec 1.15.2",
+ "smallvec",
  "utf8_iter",
 ]
 
@@ -2211,6 +2217,12 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "112b39cec0b298b6c1999fee3e31427f74f676e4cb9879ed1a121b43661a4154"
 
+[[package]]
+name = "lzma-rust2"
+version = "0.15.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e20f57f9918e5bd7bc58c22cdd70a6afc7375d4dd9683af5f2b34bd3d2bba619"
+
 [[package]]
 name = "maplit"
 version = "1.0.2"
@@ -2337,21 +2349,6 @@ dependencies = [
  "tempfile",
 ]
 
-[[package]]
-name = "ndarray"
-version = "0.16.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "882ed72dce9365842bf196bdeedf5055305f11fc8c03dee7bb0194a6cad34841"
-dependencies = [
- "matrixmultiply",
- "num-complex",
- "num-integer",
- "num-traits",
- "portable-atomic",
- "portable-atomic-util",
- "rawpointer",
-]
-
 [[package]]
 name = "ndarray"
 version = "0.17.2"
@@ -2561,26 +2558,25 @@ dependencies = [
 
 [[package]]
 name = "ort"
-version = "2.0.0-rc.10"
+version = "2.0.0-rc.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fa7e49bd669d32d7bc2a15ec540a527e7764aec722a45467814005725bcd721"
+checksum = "4336a1e2b38848325241c72889086886004e589b7c74f335e60a8e8db5138a0b"
 dependencies = [
- "ndarray 0.16.1",
+ "ndarray",
  "ort-sys",
- "smallvec 2.0.0-alpha.10",
+ "smallvec",
  "tracing",
+ "ureq",
 ]
 
 [[package]]
 name = "ort-sys"
-version = "2.0.0-rc.10"
+version = "2.0.0-rc.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2aba9f5c7c479925205799216e7e5d07cc1d4fa76ea8058c60a9a30f6a4e890"
+checksum = "cf211e3776eea6aec988552fa118dd746d70e1b1e5e244058d1c98015f3e5872"
 dependencies = [
- "flate2",
- "pkg-config",
- "sha2 0.10.9",
- "tar",
+ "hmac-sha256",
+ "lzma-rust2",
  "ureq",
 ]
 
@@ -2615,7 +2611,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "redox_syscall",
- "smallvec 1.15.2",
+ "smallvec",
  "windows-link",
 ]
 
@@ -3064,7 +3060,7 @@ dependencies = [
  "num-traits",
  "once_cell",
  "rhai_codegen",
- "smallvec 1.15.2",
+ "smallvec",
  "smartstring",
  "thin-vec",
  "web-time",
@@ -3439,12 +3435,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "smallvec"
-version = "2.0.0-alpha.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "51d44cfb396c3caf6fbfd0ab422af02631b69ddd96d2eff0b0f0724f9024051b"
-
 [[package]]
 name = "smartstring"
 version = "1.0.1"
@@ -3532,7 +3522,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2 0.10.9",
- "smallvec 1.15.2",
+ "smallvec",
  "thiserror",
  "tokio",
  "tokio-stream",
@@ -3635,7 +3625,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2 0.11.0",
- "smallvec 1.15.2",
+ "smallvec",
  "sqlx-core",
  "stringprep",
  "thiserror",
@@ -4092,7 +4082,7 @@ checksum = "adbc64cba7137545b8044cb1fe9814f7aacf3c6b5f9b45be8bb5db538befdb26"
 dependencies = [
  "js-sys",
  "opentelemetry",
- "smallvec 1.15.2",
+ "smallvec",
  "tracing",
  "tracing-core",
  "tracing-log",
@@ -4123,7 +4113,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sharded-slab",
- "smallvec 1.15.2",
+ "smallvec",
  "thread_local",
  "tracing",
  "tracing-core",
@@ -4149,14 +4139,14 @@ dependencies = [
  "lazy_static",
  "log",
  "maplit",
- "ndarray 0.17.2",
+ "ndarray",
  "num-complex",
  "num-integer",
  "num-traits",
  "pastey",
  "rustfft",
  "serde",
- "smallvec 1.15.2",
+ "smallvec",
  "tract-data",
  "tract-linalg",
 ]
@@ -4178,14 +4168,14 @@ dependencies = [
  "lazy_static",
  "libm",
  "maplit",
- "ndarray 0.17.2",
+ "ndarray",
  "nom",
  "nom-language",
  "num-integer",
  "num-traits",
  "parking_lot",
  "scan_fmt",
- "smallvec 1.15.2",
+ "smallvec",
  "string-interner",
 ]
 
@@ -4269,7 +4259,7 @@ dependencies = [
  "memmap2",
  "num-integer",
  "prost",
- "smallvec 1.15.2",
+ "smallvec",
  "tract-extra",
  "tract-hir",
  "tract-nnef",
diff --git a/crates/conduit-vad/Cargo.toml b/crates/conduit-vad/Cargo.toml
index 9d8ece6..1fc7353 100644
--- a/crates/conduit-vad/Cargo.toml
+++ b/crates/conduit-vad/Cargo.toml
@@ -32,8 +32,8 @@ tracing.workspace = true
 # different output shapes, so neither one alone is the model. Every published
 # export fails the same way, including the one named `ifless`. `conduit-wake`
 # keeps `tract`, which loads openWakeWord fine.
-ort = { version = "=2.0.0-rc.10", optional = true }
-ndarray = { version = "0.16", optional = true }
+ort = { version = "=2.0.0-rc.13", optional = true }
+ndarray = { version = "0.17", optional = true }
 
 [dev-dependencies]
 bytes.workspace = true
diff --git a/crates/conduit-vad/src/onnx.rs b/crates/conduit-vad/src/onnx.rs
index 910888e..a10184b 100644
--- a/crates/conduit-vad/src/onnx.rs
+++ b/crates/conduit-vad/src/onnx.rs
@@ -128,17 +128,23 @@ impl Model {
         // of audio at a time on a thread Conduit already set aside for it, and a
         // backend spawning its own pool per session would contend with every other
         // stage for no gain on a workload this small.
-        let session = Session::builder()
-            .and_then(|builder| builder.with_optimization_level(GraphOptimizationLevel::Level3))
-            .and_then(|builder| builder.with_intra_threads(1))
-            .and_then(|builder| builder.with_inter_threads(1))
-            .and_then(|builder| builder.commit_from_file(path))
-            .map_err(|error| {
-                Error::Config(format!(
-                    "cannot load the Silero VAD model `{}`: {error}",
-                    path.display()
-                ))
-            })?;
+        // `ort` 2.0-rc.13 parameterises each builder-step error by the builder
+        // state, so chaining with `and_then` on a single `Result<SessionBuilder>`
+        // no longer type-checks. Threading each step through `?` and mapping the
+        // final error the same way keeps behaviour identical.
+        let build = || -> ort::Result<Session> {
+            Session::builder()?
+                .with_optimization_level(GraphOptimizationLevel::Level3)?
+                .with_intra_threads(1)?
+                .with_inter_threads(1)?
+                .commit_from_file(path)
+        };
+        let session = build().map_err(|error| {
+            Error::Config(format!(
+                "cannot load the Silero VAD model `{}`: {error}",
+                path.display()
+            ))
+        })?;
 
         Ok(Self { session: Mutex::new(session), window, sample_rate: i64::from(sample_rate) })
     }