diff --git a/extensions/matrix/src/matrix/monitor/handler.test.ts b/extensions/matrix/src/matrix/monitor/handler.test.ts
index 0eb28dadf09..6f9d353cb84 100644
--- a/extensions/matrix/src/matrix/monitor/handler.test.ts
+++ b/extensions/matrix/src/matrix/monitor/handler.test.ts
@@ -234,6 +234,30 @@ describe("matrix monitor handler pairing account scope", () => {
     );
   });
 
+  it("does not enqueue delivered text messages into system events", async () => {
+    const dispatchReplyFromConfig = vi.fn(async () => ({
+      queuedFinal: true,
+      counts: { final: 1, block: 0, tool: 0 },
+    }));
+    const { handler, enqueueSystemEvent } = createMatrixHandlerTestHarness({
+      dispatchReplyFromConfig,
+      isDirectMessage: true,
+      getMemberDisplayName: async () => "sender",
+    });
+
+    await handler(
+      "!room:example.org",
+      createMatrixTextMessageEvent({
+        eventId: "$event-system-preview",
+        body: "hello from matrix",
+        mentions: { room: true },
+      }),
+    );
+
+    expect(dispatchReplyFromConfig).toHaveBeenCalled();
+    expect(enqueueSystemEvent).not.toHaveBeenCalled();
+  });
+
   it("drops forged metadata-only mentions before agent routing", async () => {
     const { handler, recordInboundSession, resolveAgentRoute } = createMatrixHandlerTestHarness({
       isDirectMessage: false,
diff --git a/extensions/matrix/src/matrix/monitor/handler.ts b/extensions/matrix/src/matrix/monitor/handler.ts
index 85892ff5ecb..066c9cdf39a 100644
--- a/extensions/matrix/src/matrix/monitor/handler.ts
+++ b/extensions/matrix/src/matrix/monitor/handler.ts
@@ -758,7 +758,6 @@ export function createMatrixRoomMessageHandler(params: MatrixMonitorHandlerParam
         });
       }
 
-      let didSendReply = false;
       const tableMode = core.channel.text.resolveMarkdownTableMode({
         cfg,
         channel: "matrix",
@@ -811,7 +810,6 @@ export function createMatrixRoomMessageHandler(params: MatrixMonitorHandlerParam
               mediaLocalRoots,
               tableMode,
             });
-            didSendReply = true;
           },
           onError: (err: unknown, info: { kind: "tool" | "block" | "final" }) => {
             runtime.error?.(`matrix ${info.kind} reply failed: ${String(err)}`);
@@ -834,7 +832,6 @@ export function createMatrixRoomMessageHandler(params: MatrixMonitorHandlerParam
       if (!queuedFinal) {
         return;
       }
-      didSendReply = true;
       const finalCount = counts.final;
       logVerboseMessage(
         `matrix: delivered ${finalCount} reply${finalCount === 1 ? "" : "ies"} to ${replyTarget}`,