diff --git a/electron/ipc/export/native-video.test.ts b/electron/ipc/export/native-video.test.ts
index 6a1f18f2..be54d364 100644
--- a/electron/ipc/export/native-video.test.ts
+++ b/electron/ipc/export/native-video.test.ts
@@ -1078,6 +1078,47 @@ describe("validateNvidiaCudaExportSummary", () => {
 		expect(issues).toEqual([]);
 	});
 
+	it("rejects inline-audio CUDA output when the helper does not produce audio", () => {
+		const issues = validateNvidiaCudaExportSummary(
+			{
+				success: true,
+				targetFrames: 300,
+				durationSec: 10,
+				nativeSummary: {
+					success: true,
+					frames: 300,
+					sourceTimestampMode: "pts",
+					selectionStage: "timestamp-mapped-callback",
+				},
+				outputVideo: { duration: "9.999900", nb_frames: "300" },
+			},
+			{ durationSec: 10, targetFrames: 300, requiresTimelineSync: true },
+		);
+
+		expect(issues).toEqual(["missing output audio stream"]);
+	});
+
+	it("rejects inline-audio CUDA output when the probed audio stream is empty", () => {
+		const issues = validateNvidiaCudaExportSummary(
+			{
+				success: true,
+				targetFrames: 300,
+				durationSec: 10,
+				nativeSummary: {
+					success: true,
+					frames: 300,
+					sourceTimestampMode: "pts",
+					selectionStage: "timestamp-mapped-callback",
+				},
+				outputVideo: { duration: "9.999900", nb_frames: "300" },
+				outputAudio: { duration: "0.000000" },
+			},
+			{ durationSec: 10, targetFrames: 300, requiresTimelineSync: true },
+		);
+
+		expect(issues).toEqual(["output audio duration is not positive"]);
+	});
+
 	it("accepts audio CUDA output when the helper reports PTS-aligned selection", () => {
 		const issues = validateNvidiaCudaExportSummary(
 			{
diff --git a/electron/ipc/export/native-video.ts b/electron/ipc/export/native-video.ts
index 44ba69a1..13adbdd2 100644
--- a/electron/ipc/export/native-video.ts
+++ b/electron/ipc/export/native-video.ts
@@ -433,6 +433,13 @@ export function validateNvidiaCudaExportSummary(
 	if (expected.requiresTimelineSync && !isNvidiaCudaTimestampAlignedSummary(summary)) {
 		issues.push("CUDA timeline mode is not timestamp-aligned for audio export");
 	}
+	if (expected.requiresTimelineSync) {
+		if (!summary.outputAudio) {
+			issues.push("missing output audio stream");
+		} else if (outputAudioDurationSec !== null && outputAudioDurationSec <= 0) {
+			issues.push("output audio duration is not positive");
+		}
+	}
 	if (nativeFrames === null) {
 		issues.push("missing native frame count");
 	} else if (nativeFrames < minimumFrames) {
@@ -455,6 +462,7 @@ export function validateNvidiaCudaExportSummary(
 	}
 	if (
 		outputAudioDurationSec !== null &&
+		outputAudioDurationSec > 0 &&
 		Math.abs(outputAudioDurationSec - expectedDurationSec) > durationToleranceSec
 	) {
 		issues.push(