diff --git a/tracing-subscriber/src/fmt/fmt_layer.rs b/tracing-subscriber/src/fmt/fmt_layer.rs
index ea3ca92982..c206e2b2c0 100644
--- a/tracing-subscriber/src/fmt/fmt_layer.rs
+++ b/tracing-subscriber/src/fmt/fmt_layer.rs
@@ -459,6 +459,9 @@ where
         if let Some(FormattedFields { ref mut fields, .. }) =
             extensions.get_mut::<FormattedFields<N>>()
         {
+            if !values.is_empty() {
+                fields.push(' ');
+            }
             let _ = self.fmt_fields.format_fields(fields, values);
         } else {
             let mut buf = String::new();