diff --git a/internal/util-logging/src/test/scala/Escapes.scala b/internal/util-logging/src/test/scala/Escapes.scala
index 153a5da56..9078f4d59 100644
--- a/internal/util-logging/src/test/scala/Escapes.scala
+++ b/internal/util-logging/src/test/scala/Escapes.scala
@@ -61,6 +61,7 @@ object Escapes extends Properties("Escapes") {
   final case class EscapeAndNot(escape: EscapeSequence, notEscape: String) {
     override def toString = s"EscapeAntNot(escape = [$escape], notEscape = [${notEscape.map(_.toInt)}])"
   }
+  // 2.10.5 warns on "implicit numeric widening" but it looks like a bug: https://issues.scala-lang.org/browse/SI-8450
   final case class EscapeSequence(content: String, terminator: Char) {
     if (!content.isEmpty) {
       assert(content.tail.forall(c => !isEscapeTerminator(c)), "Escape sequence content contains an escape terminator: '" + content + "'")