diff --git a/src/lib/ai/coach/conversation-summary.ts b/src/lib/ai/coach/conversation-summary.ts
index 074fc7c9d..41d7306b5 100644
--- a/src/lib/ai/coach/conversation-summary.ts
+++ b/src/lib/ai/coach/conversation-summary.ts
@@ -182,6 +182,9 @@ export async function refreshConversationSummary(
         // fail-closed like every other decrypt in the Coach stack.
         return [];
       }
+      // #781 — skip empty bodies: a cancelled-turn marker (an empty
+      // assistant row closing an aborted turn) carries no content to fold.
+      if (!content.trim()) return [];
       return [{ role: m.role === "assistant" ? "assistant" : "user", content }];
     });
 
diff --git a/src/lib/ai/coach/facts.ts b/src/lib/ai/coach/facts.ts
index 265598d64..8d3921c19 100644
--- a/src/lib/ai/coach/facts.ts
+++ b/src/lib/ai/coach/facts.ts
@@ -255,6 +255,9 @@ async function loadRecentTurns(
   for (const m of [...row.messages].reverse()) {
     const content = decryptOrNull(m.encryptedContent);
     if (content === null) continue;
+    // #781 — skip empty bodies: a cancelled-turn marker (an empty assistant
+    // row closing an aborted turn) carries nothing to extract from.
+    if (!content.trim()) continue;
     turns.push({ role: m.role, content });
   }
   return turns;