diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdb24614e3..db452e002b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,30 @@
+## v0.5.1165 — fix(perry-ffi): unbreak the `cargo test -p perry-ffi` link on Linux
+
+The `cargo-test` CI gate started failing after v0.5.1164 (#5083, the http2
+`server.close()` timer-id collision fix). That PR added a perry-runtime hook,
+`js_register_ffi_handle_exists_probe`, declared as an `extern "C"` in
+`crates/perry-ffi/src/handle.rs` and called from
+`ensure_handle_exists_probe_registered`, which `register_handle` invokes
+lazily on first handle creation.
+
+In the real `perry` binary the symbol resolves because perry-runtime is always
+linked in. But the **`perry-ffi` lib-test binary does not link perry-runtime**,
+so the symbol is undefined there. `perry-ffi`'s unit tests (`round_trip_simple_value`,
+`handles_are_unique`, …) all call `register_handle`, so the probe call sits on
+a test-reachable path and survives `--gc-sections`. On Linux `ld` an undefined
+reference is a hard link error (`undefined reference to
+'js_register_ffi_handle_exists_probe'`), aborting the gate. macOS's linker
+resolves it lazily, so it passed locally. The crate's other runtime hooks
+(`perry_ffi_gc_register_*`) stay undefined harmlessly: no test-reachable code
+calls them, so the linker drops their references.
+
+Fix: split the probe out of the shared `extern "C"` block into a
+`#[cfg(not(test))]` extern declaration (production, unchanged) plus a
+`#[cfg(test)] #[no_mangle]` no-op definition that gives the lib-test binary a
+local symbol to link against. Production codegen is byte-identical; only the
+test binary gains the stub. `cargo test -p perry-ffi` now links and passes
+(13 tests).
+
 ## v0.5.1164 — perf(codegen): integer-specialize `i < n` loop guards when the bound is `any`/untyped
 
 Tight integer loops whose bound is **not statically typed `number`** — most
diff --git a/CLAUDE.md b/CLAUDE.md
index 72e5153915..763b2dcf40 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and LLVM for code generation.
 
-**Current Version:** 0.5.1164
+**Current Version:** 0.5.1165
 
 
 ## TypeScript Parity Status
diff --git a/Cargo.lock b/Cargo.lock
index 1cdfe4d908..dc0defc639 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5283,7 +5283,7 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "perry"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "base64",
@@ -5338,14 +5338,14 @@ dependencies = [
 
 [[package]]
 name = "perry-api-manifest"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "perry-audio-miniaudio"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "cc",
  "libc",
@@ -5353,7 +5353,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "log",
@@ -5368,7 +5368,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-arkts"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5377,7 +5377,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-glance"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5385,7 +5385,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-js"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-dispatch",
@@ -5395,7 +5395,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-swiftui"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5404,7 +5404,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wasm"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "base64",
@@ -5417,7 +5417,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wear-tiles"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5425,7 +5425,7 @@ dependencies = [
 
 [[package]]
 name = "perry-container-compose"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -5454,14 +5454,14 @@ dependencies = [
 
 [[package]]
 name = "perry-container-e2e"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
 ]
 
 [[package]]
 name = "perry-diagnostics"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "serde",
  "serde_json",
@@ -5469,7 +5469,7 @@ dependencies = [
 
 [[package]]
 name = "perry-dispatch"
-version = "0.5.1164"
+version = "0.5.1165"
 
 [[package]]
 name = "perry-doc-fixture-my-bindings"
@@ -5480,7 +5480,7 @@ dependencies = [
 
 [[package]]
 name = "perry-doc-tests"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "clap",
@@ -5495,14 +5495,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ads"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-argon2"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "argon2",
  "perry-ffi",
@@ -5510,7 +5510,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-axios"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "reqwest",
@@ -5519,7 +5519,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-bcrypt"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "bcrypt",
  "perry-ffi",
@@ -5527,7 +5527,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-better-sqlite3"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "rusqlite",
@@ -5535,7 +5535,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cheerio"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "scraper",
@@ -5543,7 +5543,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-commander"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5551,7 +5551,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cron"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "chrono",
  "cron 0.16.0",
@@ -5561,7 +5561,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dayjs"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5569,7 +5569,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-decimal"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "rust_decimal",
@@ -5577,7 +5577,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dotenv"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "serde_json",
@@ -5585,7 +5585,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ethers"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "rand 0.8.6",
@@ -5593,7 +5593,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-events"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5601,14 +5601,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-exponential-backoff"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-fastify"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5625,7 +5625,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-fetch"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5637,7 +5637,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "lazy_static",
  "perry-ext-http-server",
@@ -5650,7 +5650,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http-server"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "bytes",
  "h2",
@@ -5673,7 +5673,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ioredis"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5683,7 +5683,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-jsonwebtoken"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "jsonwebtoken",
@@ -5694,7 +5694,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-lru-cache"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "lru",
  "perry-ffi",
@@ -5702,7 +5702,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-moment"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5710,7 +5710,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mongodb"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "bson",
  "futures-util",
@@ -5722,7 +5722,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mysql2"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5732,7 +5732,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nanoid"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "nanoid",
  "perry-ffi",
@@ -5741,7 +5741,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-net"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5753,7 +5753,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nodemailer"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "lettre",
  "perry-ffi",
@@ -5763,7 +5763,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pdf"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "printpdf",
@@ -5771,7 +5771,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pg"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "sqlx",
@@ -5780,7 +5780,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ratelimit"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "governor",
  "perry-ffi",
@@ -5788,7 +5788,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-sharp"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "image",
@@ -5797,14 +5797,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-slugify"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-streams"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5813,7 +5813,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-uuid"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "uuid",
@@ -5821,7 +5821,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-validator"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ffi",
  "regex",
@@ -5831,7 +5831,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ws"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "futures-util",
  "lazy_static",
@@ -5843,7 +5843,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-zlib"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "brotli",
  "flate2",
@@ -5852,7 +5852,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ffi"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "dashmap",
  "once_cell",
@@ -5861,7 +5861,7 @@ dependencies = [
 
 [[package]]
 name = "perry-hir"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-api-manifest",
@@ -5878,7 +5878,7 @@ dependencies = [
 
 [[package]]
 name = "perry-parser"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-diagnostics",
@@ -5890,7 +5890,7 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "base64",
@@ -5922,7 +5922,7 @@ dependencies = [
 
 [[package]]
 name = "perry-stdlib"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "aes 0.8.4",
  "aes-gcm",
@@ -6014,7 +6014,7 @@ dependencies = [
 
 [[package]]
 name = "perry-transform"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -6024,7 +6024,7 @@ dependencies = [
 
 [[package]]
 name = "perry-types"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "anyhow",
  "thiserror 1.0.69",
@@ -6032,14 +6032,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ui-model",
 ]
 
 [[package]]
 name = "perry-ui-android"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "itoa",
@@ -6056,7 +6056,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-geisterhand"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "rand 0.8.6",
  "serde",
@@ -6066,7 +6066,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-gtk4"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "cairo-rs",
@@ -6089,7 +6089,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-ios"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "block2",
@@ -6105,7 +6105,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-macos"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "block2",
@@ -6120,7 +6120,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-model"
-version = "0.5.1164"
+version = "0.5.1165"
 
 [[package]]
 name = "perry-ui-test"
@@ -6128,11 +6128,11 @@ version = "0.1.0"
 
 [[package]]
 name = "perry-ui-testkit"
-version = "0.5.1164"
+version = "0.5.1165"
 
 [[package]]
 name = "perry-ui-tvos"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "block2",
@@ -6148,7 +6148,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-visionos"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "block2",
@@ -6164,7 +6164,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-watchos"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "block2",
  "libc",
@@ -6177,7 +6177,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "libc",
@@ -6194,14 +6194,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows-winui"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "perry-ui-windows",
 ]
 
 [[package]]
 name = "perry-updater"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "base64",
  "ed25519-dalek",
@@ -6215,7 +6215,7 @@ dependencies = [
 
 [[package]]
 name = "perry-wasm-host"
-version = "0.5.1164"
+version = "0.5.1165"
 dependencies = [
  "wasmi",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index ef912688f1..193c6730cb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -201,7 +201,7 @@ codegen-units = 16
 opt-level = "s"       # Optimize for size in stdlib
 
 [workspace.package]
-version = "0.5.1164"
+version = "0.5.1165"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"
diff --git a/crates/perry-ffi/src/handle.rs b/crates/perry-ffi/src/handle.rs
index 062f24d3d3..92e138f4da 100644
--- a/crates/perry-ffi/src/handle.rs
+++ b/crates/perry-ffi/src/handle.rs
@@ -105,13 +105,29 @@ extern "C" {
         scanner_id: usize,
         scanner: PerryFfiNamedMutableRootScanner,
     );
-    /// perry-runtime hook: register a probe the runtime's generic method
-    /// dispatcher consults to tell a `register_handle` id apart from a Node
-    /// timer id (both occupy the pointer-tagged small-integer band). Resolved
-    /// at final link (perry-runtime is always linked into the binary).
+}
+
+// perry-runtime hook: register a probe the runtime's generic method
+// dispatcher consults to tell a `register_handle` id apart from a Node
+// timer id (both occupy the pointer-tagged small-integer band). Resolved
+// at final link (perry-runtime is always linked into the binary).
+//
+// The `perry-ffi` lib-test binary does not link perry-runtime, so under
+// `cfg(test)` this is a local no-op definition instead of an undefined
+// extern — otherwise the test link fails on linkers that don't lazily
+// resolve undefined symbols (Linux `ld`). The other runtime hooks above
+// stay undefined harmlessly: no test-reachable code calls them, so
+// `--gc-sections` drops their references; this probe is the only hook on
+// `register_handle`'s hot path, which the unit tests exercise.
+#[cfg(not(test))]
+extern "C" {
     fn js_register_ffi_handle_exists_probe(probe: extern "C" fn(handle: i64) -> bool);
 }
 
+#[cfg(test)]
+#[no_mangle]
+extern "C" fn js_register_ffi_handle_exists_probe(_probe: extern "C" fn(handle: i64) -> bool) {}
+
 /// Probe handed to perry-runtime: is `handle` a live entry in this registry?
 /// Used to disambiguate a `POINTER_TAG | id` value that names both a live
 /// handle and a live timer (e.g. HTTP/2 server handle 1 vs `setTimeout` id 1),