diff --git a/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala b/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala
index 800af19e9f78..76fcb77d8c30 100644
--- a/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala
+++ b/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala
@@ -582,7 +582,7 @@ object ProtoTypes {
     override def isMatchedBy(tp: Type, keepConstraint: Boolean)(using Context): Boolean =
       canInstantiate(tp) || tp.member(nme.apply).hasAltWith(d => canInstantiate(d.info))
 
-    def derivedPolyProto(targs: List[Tree], resultType: Type): PolyProto =
+    def derivedPolyProto(targs: List[Tree], resType: Type): PolyProto =
       if ((targs eq this.targs) && (resType eq this.resType)) this
       else PolyProto(targs, resType)
 
diff --git a/tests/neg/i14145.scala b/tests/neg/i14145.scala
new file mode 100644
index 000000000000..e9619ae9d756
--- /dev/null
+++ b/tests/neg/i14145.scala
@@ -0,0 +1,4 @@
+val l: List[Option[Int]] = List(None, Some(1), None)
+
+@main def m15 =
+  l.collectFirst(Some.unapply.unlift[Option[Int], Int]) // error