diff --git a/src/query/src/tdigest.c b/src/query/src/tdigest.c
index 94750c92cb1177982ac5a1940cb0af52a58872b4..b3a557653d4c4622d45cf8946d952ceb9e80fc16 100644
--- a/src/query/src/tdigest.c
+++ b/src/query/src/tdigest.c
@@ -303,7 +303,7 @@ void tdigestMerge(TDigest *t1, TDigest *t2) {
     int num_points = t2->num_buffered_pts;
     for(int i = num_points - 1; i >= 0; i--) {
         Point* p = t2->buffered_pts + i;
-        tdigestAdd(t1, p->value, p->value);
+        tdigestAdd(t1, p->value, p->weight);
         t2->num_buffered_pts --;
     }
     // centroids