diff --git a/src/lib/ai/coach/__tests__/snapshot-new-metrics.test.ts b/src/lib/ai/coach/__tests__/snapshot-new-metrics.test.ts
index 97f0e68be..1d4c27189 100644
--- a/src/lib/ai/coach/__tests__/snapshot-new-metrics.test.ts
+++ b/src/lib/ai/coach/__tests__/snapshot-new-metrics.test.ts
@@ -94,6 +94,9 @@ describe("buildCoachSnapshot — Apple Health additive metrics (v1.4.23)", () =>
     // for 60 s; reset between tests so each fixture is read fresh.
     __resetCoachSnapshotCacheForTests();
     resolveModuleMapMock.mockResolvedValue(allModulesEnabled());
+    // No readings unless a case seeds its own; the case that only inspects
+    // the query used to inherit whatever rows the case before it left.
+    prismaMock.measurement.findMany.mockResolvedValue([]);
     prismaMock.moodEntry.findMany.mockResolvedValue([]);
     prismaMock.medicationIntakeEvent.findMany.mockResolvedValue([]);
     prismaMock.medication.findMany.mockResolvedValue([]);