diff --git a/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift b/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift
index f6ac216..e5f3b16 100644
--- a/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift
+++ b/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift
@@ -651,6 +651,12 @@ struct TranscriptList: View {
             // so it sits over the composer instead of behind the floating bar; a tap bumps this
             // same request, and following resumes once the geometry reader sees the bottom.
             .onChange(of: scrollToBottomRequest) { scrollToEnd(proxy) }
+            // Warm the Markdown parse caches off the main thread whenever the row set grows —
+            // `initial: true` fires it for the batch that lands on open (the expensive case), and
+            // each later new row tops it up. Keyed on the row *count*, so streaming deltas into an
+            // existing row (which don't change the count) never re-arm it. `items.count` is O(1).
+            .onChange(of: items.count, initial: true) { _, _ in prewarmMarkdown() }
+            .onDisappear { prewarmTask?.cancel() }
         }
     }