diff --git a/packages/core/src/session/runner/llm.ts b/packages/core/src/session/runner/llm.ts
index 3495cfdc4fb..6ed210fde18 100644
--- a/packages/core/src/session/runner/llm.ts
+++ b/packages/core/src/session/runner/llm.ts
@@ -410,7 +410,9 @@ const layer = Layer.effect(
               yield* events.publish(SessionEvent.Compaction.Failed, {
                 sessionID,
                 reason: "manual",
-                error: { type: "compaction.failed", message: Cause.pretty(compacted.cause) },
+                error: Cause.hasInterruptsOnly(compacted.cause)
+                  ? { type: "aborted", message: "Compaction cancelled" }
+                  : { type: "compaction.failed", message: Cause.pretty(compacted.cause) },
                 inputID: unsettled.id,
               })
             return yield* Effect.failCause(compacted.cause)
diff --git a/packages/core/test/session-runner.test.ts b/packages/core/test/session-runner.test.ts
index 39cf62e8471..6bd8b23be14 100644
--- a/packages/core/test/session-runner.test.ts
+++ b/packages/core/test/session-runner.test.ts
@@ -1892,6 +1892,35 @@ describe("SessionRunnerLLM", () => {
     }),
   )
 
+  it.effect("records cancelled manual compaction without surfacing an internal failure", () =>
+    Effect.gen(function* () {
+      const session = yield* setup
+      response = reply.text("Earlier answer", "text-manual-interrupt-history")
+      yield* admit(session, "Earlier question")
+      yield* session.resume(sessionID)
+
+      const streamed = yield* Deferred.make<void>()
+      const partial = fragmentFixture("text", "text-manual-interrupt-summary", ["Partial summary"])
+      responseStream = Stream.concat(
+        Stream.fromIterable(partial.partialEvents),
+        Stream.fromEffect(Deferred.succeed(streamed, undefined)).pipe(Stream.flatMap(() => Stream.never)),
+      )
+      const compaction = yield* session.compact({ sessionID })
+      const run = yield* session.resume(sessionID).pipe(Effect.forkChild)
+      yield* Deferred.await(streamed)
+      yield* session.interrupt(sessionID)
+
+      yield* Fiber.await(run)
+      expect(yield* SessionPending.compaction((yield* Database.Service).db, sessionID)).toBeUndefined()
+      expect((yield* session.messages({ sessionID })).find((message) => message.id === compaction.id)).toMatchObject({
+        type: "compaction",
+        status: "failed",
+        reason: "manual",
+        error: { type: "aborted", message: "Compaction cancelled" },
+      })
+    }),
+  )
+
   it.effect("settles an admitted manual compaction when pre-start resolution throws", () =>
     Effect.gen(function* () {
       const session = yield* setup
diff --git a/packages/tui/src/routes/session/index.tsx b/packages/tui/src/routes/session/index.tsx
index adeb207940b..baad5abd137 100644
--- a/packages/tui/src/routes/session/index.tsx
+++ b/packages/tui/src/routes/session/index.tsx
@@ -1440,9 +1440,10 @@ function CompactionMessage(props: { message: Extract<SessionMessageInfo, { type:
   const ctx = use()
   const { themeV2, syntax } = useTheme()
   const status = () => props.message.status
-  const text = () => (props.message.status === "failed" ? props.message.error.message : props.message.summary)
+  const cancelled = () => props.message.status === "failed" && props.message.error.type === "aborted"
+  const text = () => (props.message.status === "failed" ? (cancelled() ? "" : props.message.error.message) : props.message.summary)
   const content = createMemo(() => text().trim())
-  const color = () => (status() === "failed" ? themeV2.text.feedback.error() : themeV2.text.subdued())
+  const color = () => (status() === "failed" && !cancelled() ? themeV2.text.feedback.error() : themeV2.text.subdued())
   return (
     <box>
       <box flexDirection="row" alignItems="center">
@@ -1454,11 +1455,14 @@ function CompactionMessage(props: { message: Extract<SessionMessageInfo, { type:
                 <spinner frames={SPINNER_FRAMES} interval={80} color={color()} />
               </Show>
             </Match>
-            <Match when={status() === "failed"}>
+            <Match when={status() === "failed" && !cancelled()}>
               <text fg={color()}>✗</text>
             </Match>
           </Switch>
           <text fg={color()}>Compaction</text>
+          <Show when={cancelled()}>
+            <text fg={color()}>· cancelled</text>
+          </Show>
         </box>
         <box border={["top"]} borderColor={color()} flexGrow={1} />
       </box>