diff --git a/src/sql/engine/expr/ob_datum_cast.cpp b/src/sql/engine/expr/ob_datum_cast.cpp
index 5b3e59eec2..23a1ff9b33 100644
--- a/src/sql/engine/expr/ob_datum_cast.cpp
+++ b/src/sql/engine/expr/ob_datum_cast.cpp
@@ -6100,7 +6100,7 @@ CAST_FUNC_NAME(bit, number)
 {
   EVAL_ARG()
   {
-    int64_t in_val = child_res->get_uint();
+    uint64_t in_val = child_res->get_uint();
     ObNumStackOnceAlloc tmp_alloc;
     number::ObNumber number;
     if (OB_FAIL(number.from(in_val, tmp_alloc))) {
@@ -6357,7 +6357,7 @@ CAST_FUNC_NAME(bit, decimalint)
 {
   EVAL_ARG()
   {
-    int64_t in_val = child_res->get_uint();
+    uint64_t in_val = child_res->get_uint();
     ObDecimalIntBuilder tmp_alloc;
     ObDecimalInt *decint = nullptr;
     int32_t val_len = 0;