diff --git a/sqlx-core/src/arguments.rs b/sqlx-core/src/arguments.rs
index 6f830e8e57..b224010334 100644
--- a/sqlx-core/src/arguments.rs
+++ b/sqlx-core/src/arguments.rs
@@ -28,7 +28,7 @@ pub trait Arguments<'q>: Send + Sized + Default {
         writer.write_str("?")
     }
 
-    fn merge(mut self, other: Self);
+    fn merge(&mut self, other: Self);
 }
 
 pub trait IntoArguments<'q, DB: Database>: Sized + Send {