diff --git a/src/scalar/mod.rs b/src/scalar/mod.rs
index d5694e165dd..9a2ca3fecf5 100644
--- a/src/scalar/mod.rs
+++ b/src/scalar/mod.rs
@@ -25,7 +25,7 @@ pub use struct_::*;
 
 /// Trait object declaring an optional value with a [`DataType`].
 /// This strait is often used in APIs that accept multiple scalar types.
-pub trait Scalar: std::fmt::Debug {
+pub trait Scalar: std::fmt::Debug + Send + Sync {
     /// convert itself to
     fn as_any(&self) -> &dyn Any;