diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
index 4198c0a49797..24acce54cc4b 100644
--- a/compiler/src/dotty/tools/dotc/core/Types.scala
+++ b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -3014,7 +3014,7 @@ object Types {
     private[Types] var opened: Boolean = false
     private[Types] var openedTwice: Boolean = false
 
-    val parent: Type = parentExp(this)
+    val parent: Type = parentExp(this: @unchecked)
 
     private var myRecThis: RecThis | Null = null
 
@@ -3705,8 +3705,8 @@ object Types {
 
     type This = MethodType
 
-    val paramInfos: List[Type] = paramInfosExp(this)
-    val resType: Type = resultTypeExp(this)
+    val paramInfos: List[Type] = paramInfosExp(this: @unchecked)
+    val resType: Type = resultTypeExp(this: @unchecked)
     assert(resType.exists)
 
     def companion: MethodTypeCompanion
@@ -3879,8 +3879,8 @@ object Types {
     type This = HKTypeLambda
     def companion: HKTypeLambda.type = HKTypeLambda
 
-    val paramInfos: List[TypeBounds] = paramInfosExp(this)
-    val resType: Type = resultTypeExp(this)
+    val paramInfos: List[TypeBounds] = paramInfosExp(this: @unchecked)
+    val resType: Type = resultTypeExp(this: @unchecked)
 
     private def setVariances(tparams: List[LambdaParam], vs: List[Variance]): Unit =
       if tparams.nonEmpty then
@@ -3948,8 +3948,8 @@ object Types {
     type This = PolyType
     def companion: PolyType.type = PolyType
 
-    val paramInfos: List[TypeBounds] = paramInfosExp(this)
-    val resType: Type = resultTypeExp(this)
+    val paramInfos: List[TypeBounds] = paramInfosExp(this: @unchecked)
+    val resType: Type = resultTypeExp(this: @unchecked)
 
     assert(resType.isInstanceOf[TermType], this)
     assert(paramNames.nonEmpty)