diff --git a/src/annotations/outlineRungs.js b/src/annotations/outlineRungs.js
index 0d5e965c8..88a2361e4 100644
--- a/src/annotations/outlineRungs.js
+++ b/src/annotations/outlineRungs.js
@@ -290,6 +290,9 @@ export function createOutlineRungs({
       const patch = finish(fp, asScope);
       if (patch?.ring) {
         patch.outlineCredit = provider === 'openfreemap' ? 'tiles' : 'osm';
+        // Which source answered, so a stored area names it (OpenFreeMap or
+        // Nominatim) instead of defaulting to the Overpass rungs.
+        patch.outlineSource = provider;
         ctx.credit?.(patch.outlineCredit);
         // One line per answered outline, like the resolver's own trace.
         console.log(
diff --git a/src/annotations/outlineRungs.test.mjs b/src/annotations/outlineRungs.test.mjs
index cd02a2819..6554e6f61 100644
--- a/src/annotations/outlineRungs.test.mjs
+++ b/src/annotations/outlineRungs.test.mjs
@@ -146,7 +146,7 @@ test('a street comes from tiles before the configured ladder, as merged ribbons'
   );
   assert.ok(result.ring.length > 6);
   assert.equal(result.polygons.length, 1);
-  assert.equal('outlineSource' in result, false);
+  assert.equal(result.outlineSource, 'openfreemap');
   assert.equal(run.calls.base, 0, 'the ladder is not consulted');
   assert.deepEqual(run.calls.finished, ['street']);
   assert.deepEqual(credits, ['tiles']);
@@ -416,6 +416,7 @@ test('a city with no configured Overpass is outlined by Nominatim', async () =>
   );
   assert.deepEqual(result.ring, ring);
   assert.equal(result.outlineCredit, 'osm');
+  assert.equal(result.outlineSource, 'nominatim');
   assert.deepEqual(nominatim.asks[0], {
     query: 'Toulouse',
     kind: 'city',