diff --git a/CHANGELOG.md b/CHANGELOG.md
index fa2116a63b..47ab1cb94e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - \#39 - Create SQ8H index hang if using github server version
 - \#30 - Some troubleshoot messages in Milvus do not provide enough information
 - \#48 - Config unittest failed
+- \#59 - Topk result is incorrect for small dataset
 
 ## Improvement
 - MS-552 - Add and change the easylogging library
diff --git a/core/src/scheduler/task/SearchTask.cpp b/core/src/scheduler/task/SearchTask.cpp
index b7a1e211d2..2836d41dd4 100644
--- a/core/src/scheduler/task/SearchTask.cpp
+++ b/core/src/scheduler/task/SearchTask.cpp
@@ -253,7 +253,7 @@ XSearchTask::MergeTopkToResultSet(const std::vector<int64_t>& input_ids, const s
 
         if (result[i].empty()) {
             result_buf.resize(input_k, scheduler::IdDistPair(-1, 0.0));
-            uint64_t input_k_multi_i = input_k * i;
+            uint64_t input_k_multi_i = topk * i;
             for (auto k = 0; k < input_k; ++k) {
                 uint64_t idx = input_k_multi_i + k;
                 auto& result_buf_item = result_buf[k];
@@ -266,7 +266,7 @@ XSearchTask::MergeTopkToResultSet(const std::vector<int64_t>& input_ids, const s
             result_buf.resize(output_k, scheduler::IdDistPair(-1, 0.0));
             size_t buf_k = 0, src_k = 0, tar_k = 0;
             uint64_t src_idx;
-            uint64_t input_k_multi_i = input_k * i;
+            uint64_t input_k_multi_i = topk * i;
             while (buf_k < output_k && src_k < input_k && tar_k < tar_size) {
                 src_idx = input_k_multi_i + src_k;
                 auto& result_buf_item = result_buf[buf_k];