diff --git a/crates/nu-protocol/src/ir/display.rs b/crates/nu-protocol/src/ir/display.rs
index b0fe9d5ead..d42a98c6cf 100644
--- a/crates/nu-protocol/src/ir/display.rs
+++ b/crates/nu-protocol/src/ir/display.rs
@@ -157,7 +157,7 @@ impl fmt::Display for FmtCallArgs<'_> {
         f.write_char('[')?;
         for index in 0..self.args_len {
             if index != 0 {
-                f.write_char(' ')?;
+                f.write_str(", ")?;
             }
             if let Some(arg) = self.call_args.get(self.args_start + index) {
                 match arg {