diff --git a/be/src/vec/functions/function_unary_arithmetic.h b/be/src/vec/functions/function_unary_arithmetic.h
index c92ceb54d1..8113f42179 100644
--- a/be/src/vec/functions/function_unary_arithmetic.h
+++ b/be/src/vec/functions/function_unary_arithmetic.h
@@ -54,14 +54,17 @@ template <typename>
 struct AbsImpl;
 template <typename>
 struct NegativeImpl;
+template <typename>
+struct PositiveImpl;
 
 /// Used to indicate undefined operation
 struct InvalidType;
 
 template <template <typename> class Op, typename Name, bool is_injective>
 class FunctionUnaryArithmetic : public IFunction {
-    static constexpr bool allow_decimal =
-            std::is_same_v<Op<Int8>, NegativeImpl<Int8>> || std::is_same_v<Op<Int8>, AbsImpl<Int8>>;
+    static constexpr bool allow_decimal = std::is_same_v<Op<Int8>, NegativeImpl<Int8>> ||
+                                          std::is_same_v<Op<Int8>, AbsImpl<Int8>> ||
+                                          std::is_same_v<Op<Int8>, PositiveImpl<Int8>>;
 
     template <typename F>
     static bool cast_type(const IDataType* type, F&& f) {