diff --git a/dphon/console.py b/dphon/console.py
index a2b7dc9..99b1b29 100644
--- a/dphon/console.py
+++ b/dphon/console.py
@@ -140,6 +140,6 @@ def _add_span_context(self, span: Span) -> Tuple[str, str]:
         context_left = span.doc[span.start - self.context : span.start]
         context_right = span.doc[span.end : span.end + self.context]
         return (
-            f"[context]{context_left.text.rjust(self.context, "　")}[/context]",
-            f"[context]{context_right.text.ljust(self.context, "　")}[/context]",
+            f"[context]{context_left.text.rjust(self.context, '　')}[/context]",
+            f"[context]{context_right.text.ljust(self.context, '　')}[/context]",
         )