diff --git a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
index 67853001d8f0..c94724faf4d4 100644
--- a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
@@ -379,6 +379,7 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
                 // avoid type aliases for tuples
                 Right(MirrorSource.GenericTuple(types))
               case _ => reduce(tp.underlying)
+          case tp: MatchType => reduce(tp.normalized)
           case _ => reduce(tp.superType)
       case tp @ AndType(l, r) =>
         for
diff --git a/tests/pos/i19198.scala b/tests/pos/i19198.scala
new file mode 100644
index 000000000000..23550aac807f
--- /dev/null
+++ b/tests/pos/i19198.scala
@@ -0,0 +1,13 @@
+import deriving.Mirror
+import compiletime.summonInline
+
+inline def check1[Tps <: NonEmptyTuple]: Unit =
+  summonInline[Mirror.Of[Tuple.Head[Tps]]]
+
+inline def check2[Tps <: NonEmptyTuple]: Unit =
+  type FromType = Tuple.Head[Tps]
+  summonInline[Mirror.Of[FromType]]
+
+@main def Test: Unit =
+  check1[Option[Int] *: EmptyTuple] // Ok
+  check2[Option[Int] *: EmptyTuple] // Error: FromType is widened to Any in Syntheziser