diff --git a/web/lib/preview-deployments.ts b/web/lib/preview-deployments.ts
index c7d26f61..015a1268 100644
--- a/web/lib/preview-deployments.ts
+++ b/web/lib/preview-deployments.ts
@@ -84,8 +84,12 @@ async function updatePreviewPullRequestComment(input: {
 		input.previewUrl
 			? `**Preview:** [Open preview](${input.previewUrl})`
 			: "**Preview:** No public URL configured",
-		"",
-		`<sub>${escapeGitHubCommentText(input.description.substring(0, 500))}</sub>`,
+		...(input.state === "failure"
+			? [
+					"",
+					`<sub>${escapeGitHubCommentText(input.description.substring(0, 500))}</sub>`,
+				]
+			: []),
 	].join("\n");
 	await upsertGitHubPullRequestComment(
 		input.installationId,
diff --git a/web/tests/preview-deployments.test.ts b/web/tests/preview-deployments.test.ts
index 8e6efd0f..f4108b77 100644
--- a/web/tests/preview-deployments.test.ts
+++ b/web/tests/preview-deployments.test.ts
@@ -404,6 +404,9 @@ describe("preview service cloning", () => {
 			}),
 		);
 		expect(mocks.upsertGitHubPullRequestComment).toHaveBeenCalledTimes(2);
+		expect(
+			mocks.upsertGitHubPullRequestComment.mock.calls[0]?.[4],
+		).not.toContain("<sub>");
 		expect(mocks.upsertGitHubPullRequestComment).toHaveBeenLastCalledWith(
 			101,
 			"acme/app",