diff --git a/test/dotc/tests.scala b/test/dotc/tests.scala
index 22981b8378c2..c07b966c60c4 100644
--- a/test/dotc/tests.scala
+++ b/test/dotc/tests.scala
@@ -175,7 +175,7 @@ class tests extends CompilerTest {
   val stdlibFiles = Source.fromFile("./test/dotc/scala-collections.whitelist", "UTF8").getLines()
    .map(_.trim) // allow identation
    .filter(!_.startsWith("#")) // allow comment lines prefixed by #
-   .map(_.takeWhile(_ != "#").trim) // allow comments in the end of line
+   .map(_.takeWhile(_ != '#').trim) // allow comments in the end of line
    .filter(_.nonEmpty)
    .toList