diff --git a/CHANGELOG.md b/CHANGELOG.md
index ffc5e9a..2dcb8a8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## v3.11.1 — 2026-04-21
+
+### Fixes
+- Concurrency slot leak on subprocess timeout (#37). The request-timeout handler called `proc.kill("SIGTERM")` without decrementing `stats.activeRequests`. A subprocess stuck in a syscall that ignored SIGTERM would hold its slot until (or beyond) the 5s SIGKILL escalation actually reaped it. Slot release is now wired to `proc.once("exit", cleanup)` so every termination path — normal close, error, SIGTERM, SIGKILL — releases the slot exactly once.
+
 ## v3.11.0 — 2026-04-20
 
 ### Features
diff --git a/package.json b/package.json
index f3b6514..581c504 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "openclaw-claude-proxy",
-  "version": "3.11.0",
+  "version": "3.11.1",
   "description": "OCP (Open Claude Proxy) — use your Claude Pro/Max subscription as an OpenAI-compatible API for any IDE. Works with Cline, OpenCode, Aider, Continue.dev, OpenClaw, and more.",
   "type": "module",
   "bin": {
diff --git a/server.mjs b/server.mjs
index 60f52ae..83fc913 100644
--- a/server.mjs
+++ b/server.mjs
@@ -444,6 +444,15 @@ function spawnClaudeProcess(model, messages, conversationId) {
     stats.activeRequests--;
   }
 
+  // Guarantee slot release on ANY exit path (normal close, error, timeout kill,
+  // SIGKILL escalation). The 'exit' event fires before 'close' and runs even
+  // if stdio pipes stay open. Fixes #37: the timeout path called
+  // proc.kill('SIGTERM') without decrementing the concurrency counter, so a
+  // stuck subprocess that ignored SIGTERM could leak its slot until (or
+  // beyond) the SIGKILL escalation actually reaped it. cleanup() is idempotent
+  // so this listener is safe alongside the existing 'close'/'error' paths.
+  proc.once("exit", cleanup);
+
   function handleSessionFailure() {
     if (sessionInfo?.resume && conversationId) {
       console.warn(`[session] resume failed for ${conversationId.slice(0, 12)}..., removing stale session`);