1 files changed, 13 insertions, 5 deletions
diff --git a/src/dotty/tools/dotc/typer/Namer.scala b/src/dotty/tools/dotc/typer/Namer.scala
index 78f0da1f0..148cf1da7 100644
--- a/src/dotty/tools/dotc/typer/Namer.scala
+++ b/src/dotty/tools/dotc/typer/Namer.scala
@@ -114,7 +114,7 @@ trait NamerContextOps { this: Context =>
             if (param.info.isDirectRef(defn.ObjectClass)) param.info = defn.AnyType
         make.fromSymbols(params, resultType)
       }
-    if (typeParams.nonEmpty) PolyType.fromSymbols(typeParams, monotpe)
+    if (typeParams.nonEmpty) monotpe.LambdaAbstract(typeParams)
     else if (valueParamss.isEmpty) ExprType(monotpe)
     else monotpe
   }
@@ -294,7 +294,7 @@ class Namer { typer: Typer =>
         val inSuperCall1 = if (tree.mods is ParamOrAccessor) EmptyFlags else inSuperCall
           // suppress inSuperCall for constructor parameters
         val higherKinded = tree match {
-          case tree: TypeDef if tree.tparams.nonEmpty && isDeferred => HigherKinded
+          case TypeDef(_, PolyTypeTree(_, _)) if isDeferred => HigherKinded
           case _ => EmptyFlags
         }
 
@@ -616,8 +616,12 @@ class Namer { typer: Typer =>
         nestedCtx = localContext(sym).setNewScope
         myTypeParams = {
           implicit val ctx: Context = nestedCtx
-          completeParams(original.tparams)
-          original.tparams.map(symbolOfTree(_).asType)
+          val tparams = original.rhs match {
+            case PolyTypeTree(tparams, _) => tparams
+            case _ => Nil
+          }
+          completeParams(tparams)
+          tparams.map(symbolOfTree(_).asType)
         }
       }
       myTypeParams
@@ -1025,7 +1029,11 @@ class Namer { typer: Typer =>
       // inspects a TypeRef's info, instead of simply dealiasing alias types.
 
     val isDerived = tdef.rhs.isInstanceOf[untpd.DerivedTypeTree]
-    val rhsBodyType = typedAheadType(tdef.rhs).tpe
+    val rhs = tdef.rhs match {
+      case PolyTypeTree(_, body) => body
+      case rhs => rhs
+    }
+    val rhsBodyType = typedAheadType(rhs).tpe
     val rhsType = if (isDerived) rhsBodyType else abstracted(rhsBodyType)
     val unsafeInfo = rhsType match {
       case bounds: TypeBounds => bounds