diff --git a/src/discord/monitor/message-handler.process.test.ts b/src/discord/monitor/message-handler.process.test.ts
index 067273351db3..283b95a70644 100644
--- a/src/discord/monitor/message-handler.process.test.ts
+++ b/src/discord/monitor/message-handler.process.test.ts
@@ -441,6 +441,23 @@ describe("processDiscordMessage draft streaming", () => {
     expect(deliverDiscordReply).not.toHaveBeenCalled();
   });
 
+  it("delivers block payloads when blockStreaming is enabled", async () => {
+    dispatchInboundMessage.mockImplementationOnce(async (params?: DispatchInboundParams) => {
+      await params?.dispatcher.sendBlockReply({ text: "stream chunk" });
+      return { queuedFinal: true, counts: { final: 0, tool: 0, block: 1 } };
+    });
+
+    const ctx = await createBaseContext({
+      discordConfig: { streamMode: "off", blockStreaming: true },
+    });
+
+    // oxlint-disable-next-line typescript/no-explicit-any
+    await processDiscordMessage(ctx as any);
+
+    expect(deliverDiscordReply).toHaveBeenCalledTimes(1);
+    expect(deliverDiscordReply.mock.calls[0]?.[0]?.replies).toEqual([{ text: "stream chunk" }]);
+  });
+
   it("streams block previews using draft chunking", async () => {
     const draftStream = createMockDraftStream();
     createDiscordDraftStream.mockReturnValueOnce(draftStream);
diff --git a/src/discord/monitor/message-handler.process.ts b/src/discord/monitor/message-handler.process.ts
index 1c41fef76ec0..d0affba7fd88 100644
--- a/src/discord/monitor/message-handler.process.ts
+++ b/src/discord/monitor/message-handler.process.ts
@@ -557,9 +557,9 @@ export async function processDiscordMessage(ctx: DiscordMessagePreflightContext)
     humanDelay: resolveHumanDelayConfig(cfg, route.agentId),
     deliver: async (payload: ReplyPayload, info) => {
       const isFinal = info.kind === "final";
-      if (info.kind === "block") {
-        // Block payloads carry reasoning/thinking content that should not be
-        // delivered to external channels. Skip them regardless of streamMode.
+      if (info.kind === "block" && !accountBlockStreamingEnabled && !payload.isError) {
+        // In normal mode, suppress non-error block payloads to avoid duplicate
+        // previews. In blockStreaming mode we must deliver them.
         return;
       }
       if (draftStream && isFinal) {