diff --git a/src/roaring64.c b/src/roaring64.c
index 04b48ab91..cfd23b793 100644
--- a/src/roaring64.c
+++ b/src/roaring64.c
@@ -247,8 +247,9 @@ void roaring64_bitmap_add_bulk(roaring64_bitmap_t *r,
     } else {
         // We're not positioned anywhere yet or the high bits of the key
         // differ.
+        leaf_t *leaf = (leaf_t *)art_find(&r->art, high48);
         context->leaf =
-            containerptr_roaring64_bitmap_add(r, high48, low16, NULL);
+            containerptr_roaring64_bitmap_add(r, high48, low16, leaf);
         memcpy(context->high_bytes, high48, ART_KEY_BYTES);
     }
 }
diff --git a/tests/roaring64_unit.cpp b/tests/roaring64_unit.cpp
index 9423ab252..510dc5431 100644
--- a/tests/roaring64_unit.cpp
+++ b/tests/roaring64_unit.cpp
@@ -148,16 +148,30 @@ DEFINE_TEST(test_add_bulk) {
 }
 
 DEFINE_TEST(test_add_many) {
-    roaring64_bitmap_t* r = roaring64_bitmap_create();
-    std::array<uint64_t, 1000> vals;
-    std::iota(vals.begin(), vals.end(), 0);
+    {
+        roaring64_bitmap_t* r = roaring64_bitmap_create();
+        std::array<uint64_t, 1000> vals;
+        std::iota(vals.begin(), vals.end(), 0);
 
-    roaring64_bitmap_add_many(r, vals.size(), vals.data());
-    for (uint64_t i = 0; i < 1000; ++i) {
-        assert_true(roaring64_bitmap_contains(r, vals[i]));
+        roaring64_bitmap_add_many(r, vals.size(), vals.data());
+        for (uint64_t i = 0; i < 1000; ++i) {
+            assert_true(roaring64_bitmap_contains(r, vals[i]));
+        }
+
+        roaring64_bitmap_free(r);
     }
 
-    roaring64_bitmap_free(r);
+    {
+        // Add many_where value already exists
+        roaring64_bitmap_t* r = roaring64_bitmap_create();
+        uint64_t value = 0;
+        roaring64_bitmap_add(r, value);
+        assert_true(roaring64_bitmap_contains(r, value));
+        roaring64_bitmap_add_many(r, 1, &value);
+        assert_true(roaring64_bitmap_contains(r, value));
+        assert_int_equal(roaring64_bitmap_get_cardinality(r), 1);
+        roaring64_bitmap_free(r);
+    }
 }
 
 DEFINE_TEST(test_add_range_closed) {