diff --git a/be/src/vec/runtime/vdatetime_value.h b/be/src/vec/runtime/vdatetime_value.h
index 6e46ffbe5d3776..dc7ba70b0b04ac 100644
--- a/be/src/vec/runtime/vdatetime_value.h
+++ b/be/src/vec/runtime/vdatetime_value.h
@@ -398,11 +398,11 @@ class VecDateTimeValue { // Now this type is a temp solution with little changes
     // for performance of checking, may return false when just APPROACH BUT NOT REACH max_valid_length.
     // so need a little big buffer and its length as max_valid_length to make sure store valid data.
     // to make sure of this. make the buffer size = <data_need_length> + SAFE_FORMAT_STRING_MARGIN. and pass this size as max_valid_length
-    bool to_format_string_conservative(const char* format, int len, char* to,
-                                       int max_valid_length) const;
+    bool to_format_string_conservative(const char* format, size_t len, char* to,
+                                       size_t max_valid_length) const;
 
     // compute the length of data format pattern
-    static int compute_format_len(const char* format, int len);
+    static int compute_format_len(const char* format, size_t len);
 
     // Return true if range or date is invalid
     static bool check_range(uint32_t year, uint32_t month, uint32_t day, uint32_t hour,