diff --git a/paddle/fluid/operators/lookup_table_op.h b/paddle/fluid/operators/lookup_table_op.h
index 8760cc2ee9643bf7a9569c926d8a85588c77832e..fff5edda62d4b115605a4cab35ed5457b4db5f21 100644
--- a/paddle/fluid/operators/lookup_table_op.h
+++ b/paddle/fluid/operators/lookup_table_op.h
@@ -30,12 +30,12 @@ using LoDTensor = framework::LoDTensor;
 using SelectedRows = framework::SelectedRows;
 using DDim = framework::DDim;
 
-static const int64_t kNoPadding = -1;
+static constexpr int64_t kNoPadding = -1;
 
 inline size_t getIndex(const std::vector<int64_t> &rows, int64_t value) {
   auto it = std::find(rows.begin(), rows.end(), value);
   PADDLE_ENFORCE(it != rows.end(), "id should be in rows");
-  return std::distance(rows.begin(), it);
+  return static_cast<size_t>(std::distance(rows.begin(), it));
 }
 
 template <typename T>