diff --git a/backend/src/routes/properties.js b/backend/src/routes/properties.js
index 2b2c255..09ec203 100644
--- a/backend/src/routes/properties.js
+++ b/backend/src/routes/properties.js
@@ -371,8 +371,14 @@ router.post('/:id/sections', validateParams(idParamSchema), validateRequest(lawn
     // Sanitize polygon before storing
     let poly = polygonData;
     try {
-      const cleaned = sanitizePolygon(polygonData?.coordinates?.[0] || []);
-      poly = { ...polygonData, coordinates: [cleaned] };
+      const ring = polygonData?.coordinates?.[0] || [];
+      // For GPS-captured shapes, keep the user's ring as-is to avoid over-simplifying
+      if (captureMethod === 'gps_points' || captureMethod === 'gps_trace') {
+        poly = { ...polygonData, coordinates: [ring] };
+      } else {
+        const cleaned = sanitizePolygon(ring);
+        poly = { ...polygonData, coordinates: [cleaned && cleaned.length >= 3 ? cleaned : ring] };
+      }
     } catch {}
 
     const result = await pool.query(
@@ -446,8 +452,13 @@ router.put('/:propertyId/sections/:sectionId', async (req, res, next) => {
 
     let upoly = polygonData;
     try {
-      const cleaned = sanitizePolygon(polygonData?.coordinates?.[0] || []);
-      upoly = { ...polygonData, coordinates: [cleaned] };
+      const ring = polygonData?.coordinates?.[0] || [];
+      if (captureMethod === 'gps_points' || captureMethod === 'gps_trace') {
+        upoly = { ...polygonData, coordinates: [ring] };
+      } else {
+        const cleaned = sanitizePolygon(ring);
+        upoly = { ...polygonData, coordinates: [cleaned && cleaned.length >= 3 ? cleaned : ring] };
+      }
     } catch {}
 
     const result = await pool.query(