diff --git a/crates/gpui3/src/style_helpers.rs b/crates/gpui3/src/style_helpers.rs
index b58da2fbfc762c1d0c1af1a86200454d32101997..9bdcf7fafbb784707b89138d8236a8d495564d92 100644
--- a/crates/gpui3/src/style_helpers.rs
+++ b/crates/gpui3/src/style_helpers.rs
@@ -5,7 +5,7 @@ use crate::{
 };
 use smallvec::smallvec;
 
-pub trait StyleHelpers: Styled<Style = Style> {
+pub trait StyleHelpers: Sized + Styled<Style = Style> {
     gpui3_macros::style_helpers!();
 
     fn h(mut self, height: Length) -> Self {