2 files changed, 3 insertions, 3 deletions
diff --git a/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala b/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala
index cdc28b23f..7fb9ba302 100644
--- a/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala
+++ b/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala
@@ -107,7 +107,7 @@ trait FullParameterization {
       val firstArgType = if (liftThisType) thisParamType & clazz.thisType else thisParamType
       MethodType(nme.SELF :: Nil)(
           mt => firstArgType :: Nil,
-          mt => mapClassParams(origResult).substThisUnlessStatic(clazz, MethodParam(mt, 0)))
+          mt => mapClassParams(origResult).substThisUnlessStatic(clazz, mt.newParamRef(0)))
     }
 
     /** Replace class type parameters by the added type parameters of the polytype `pt` */
diff --git a/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala b/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
index 3c11827fc..8907cc4dd 100644
--- a/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
+++ b/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
@@ -180,7 +180,7 @@ class SuperAccessors(thisTransformer: DenotTransformer) {
           case tpe: PolyType =>
             tpe.derivedPolyType(tpe.paramNames, tpe.paramBounds, accTypeOf(tpe.resultType))
           case _ =>
-            MethodType(receiverType :: Nil)(mt => tpe.substThis(sym.owner.asClass, MethodParam(mt, 0)))
+            MethodType(receiverType :: Nil)(mt => tpe.substThis(sym.owner.asClass, mt.newParamRef(0)))
         }
         accTypeOf(sym.info)
       }
@@ -232,7 +232,7 @@ class SuperAccessors(thisTransformer: DenotTransformer) {
         case tpe: PolyType =>
           tpe.derivedPolyType(tpe.paramNames, tpe.paramBounds, accTypeOf(tpe.resultType))
         case _ =>
-          MethodType(receiverType :: Nil)(mt => tpe.substThis(sym.owner.asClass, MethodParam(mt, 0)))
+          MethodType(receiverType :: Nil)(mt => tpe.substThis(sym.owner.asClass, mt.newParamRef(0)))
       }
       val accType = accTypeOf(sym.info)
       val protectedAccessor = clazz.info.decl(accName).suchThat(_.signature == accType.signature).symbol orElse {