diff --git a/packages/opencode/src/bus/global.ts b/packages/opencode/src/bus/global.ts
index 3cfd453624..54d3dab3d6 100644
--- a/packages/opencode/src/bus/global.ts
+++ b/packages/opencode/src/bus/global.ts
@@ -11,12 +11,24 @@ export type GlobalEvent = {
 class GlobalBusEmitter extends EventEmitter<{
   event: [GlobalEvent]
 }> {
-  override emit(eventName: "event", event: GlobalEvent): boolean {
-    if (event.payload && typeof event.payload === "object" && !("id" in event.payload)) {
+  // altimate_change start — upstream_fix: keep the override assignable to the base.
+  // `EventEmitter<T>` declares `emit` across several overloads, one of which is
+  // `(eventName: string | symbol, ...args: any[])`. An override has to be
+  // assignable to all of them, and a lone `(eventName: "event", event:
+  // GlobalEvent)` is not — newer `@types/node` rejects it with "Type 'any[]' is
+  // not assignable to type '[event: GlobalEvent]'", which fails `bun typecheck`
+  // and so blocks `git push` on unmodified code. The public overload keeps call
+  // sites typed; the implementation signature is what satisfies the base.
+  override emit(eventName: "event", event: GlobalEvent): boolean
+  override emit(eventName: string | symbol, ...args: any[]): boolean
+  override emit(eventName: string | symbol, ...args: any[]): boolean {
+    const event = args[0] as GlobalEvent | undefined
+    if (eventName === "event" && event?.payload && typeof event.payload === "object" && !("id" in event.payload)) {
       event.payload.id = event.payload.syncEvent?.id ?? Identifier.create("evt", "ascending")
     }
-    return super.emit(eventName, event)
+    return super.emit(eventName as "event", ...(args as [GlobalEvent]))
   }
+  // altimate_change end
 }
 
 export const GlobalBus = new GlobalBusEmitter()
diff --git a/packages/opencode/test/bus/global-emit.test.ts b/packages/opencode/test/bus/global-emit.test.ts
new file mode 100644
index 0000000000..82f572a8d9
--- /dev/null
+++ b/packages/opencode/test/bus/global-emit.test.ts
@@ -0,0 +1,57 @@
+// altimate_change start — upstream_fix: pin the override's assignability to the base.
+import { describe, expect, test } from "bun:test"
+import { GlobalBus, type GlobalEvent } from "@/bus/global"
+
+describe("GlobalBusEmitter.emit", () => {
+  // The regression this guards is a COMPILE error, not a runtime one: a lone
+  // `(eventName: "event", event: GlobalEvent)` override is not assignable to
+  // the base `EventEmitter<T>` overload set, which newer `@types/node` rejects
+  // with "Type 'any[]' is not assignable to type '[event: GlobalEvent]'". That
+  // failed `bun typecheck`, and so blocked `git push` via the pre-push hook, on
+  // code nobody had touched. This assignment only compiles while the override
+  // keeps the wide implementation signature, so `tsgo` fails if it is narrowed
+  // again — the test body below merely keeps the reference alive.
+  test("stays assignable to the base EventEmitter signature", () => {
+    const wide: (eventName: string | symbol, ...args: any[]) => boolean = GlobalBus.emit.bind(GlobalBus)
+    expect(typeof wide).toBe("function")
+  })
+
+  test("stamps an id onto a payload that has none", () => {
+    const seen: GlobalEvent[] = []
+    const on = (event: GlobalEvent) => void seen.push(event)
+    GlobalBus.on("event", on)
+    try {
+      GlobalBus.emit("event", { payload: { kind: "test" } })
+      expect(seen).toHaveLength(1)
+      expect(typeof seen[0]!.payload.id).toBe("string")
+      expect(seen[0]!.payload.id).toStartWith("evt")
+    } finally {
+      GlobalBus.off("event", on)
+    }
+  })
+
+  test("leaves an existing id alone", () => {
+    const seen: GlobalEvent[] = []
+    const on = (event: GlobalEvent) => void seen.push(event)
+    GlobalBus.on("event", on)
+    try {
+      GlobalBus.emit("event", { payload: { id: "evt_already_set" } })
+      expect(seen[0]!.payload.id).toBe("evt_already_set")
+    } finally {
+      GlobalBus.off("event", on)
+    }
+  })
+
+  test("prefers the syncEvent id when the payload has none", () => {
+    const seen: GlobalEvent[] = []
+    const on = (event: GlobalEvent) => void seen.push(event)
+    GlobalBus.on("event", on)
+    try {
+      GlobalBus.emit("event", { payload: { syncEvent: { id: "evt_from_sync" } } })
+      expect(seen[0]!.payload.id).toBe("evt_from_sync")
+    } finally {
+      GlobalBus.off("event", on)
+    }
+  })
+})
+// altimate_change end