diff --git a/compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala b/compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala
index 22a32585c668..97ea32d76b2d 100644
--- a/compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala
+++ b/compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala
@@ -136,7 +136,7 @@ trait MessageRendering {
     val pageWidth = ctx.settings.pageWidth.value
     val prefix = " " * (offset - 1)
     val line = "-" * (pageWidth - offset)
-    hl(s"$prefix·$line")
+    hl(s"${prefix}·$line")
 
   /** The error message (`msg`) aligned under `pos`
     *