diff --git a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt
index b289e5bb615..466a5dbecfa 100644
--- a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt
+++ b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt
@@ -15,7 +15,6 @@ enum class ProjectionKind {
     STAR, IN, OUT, INVARIANT
 }
 
-
 object StarProjection : ConeKotlinTypeProjection(ProjectionKind.STAR)
 
 abstract class ConeKotlinTypeProjectionIn : ConeKotlinTypeProjection(ProjectionKind.IN) {
@@ -26,9 +25,17 @@ abstract class ConeKotlinTypeProjectionOut : ConeKotlinTypeProjection(Projection
     abstract val type: ConeKotlinType
 }
 
-abstract class ConeKotlinType : ConeKotlinTypeProjection(ProjectionKind.INVARIANT)
+// We assume type IS an invariant type projection to prevent additional wrapper here
+// (more exactly, invariant type projection contains type)
+sealed class ConeKotlinType : ConeKotlinTypeProjection(ProjectionKind.INVARIANT)
 
-abstract class ConeSymbolBasedType : ConeKotlinType() {
+class ConeKotlinErrorType(val reason: String) : ConeKotlinType() {
+    override fun toString(): String {
+        return "<ERROR TYPE: $reason>"
+    }
+}
+
+sealed class ConeSymbolBasedType : ConeKotlinType() {
     abstract val symbol: ConeSymbol
 }
 
diff --git a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/impl/Impl.kt b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/impl/Impl.kt
index 2cbae356c81..41f3f22af15 100644
--- a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/impl/Impl.kt
+++ b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/impl/Impl.kt
@@ -18,13 +18,6 @@ class ConeKotlinTypeProjectionInImpl(override val type: ConeKotlinType) : ConeKo
 
 class ConeKotlinTypeProjectionOutImpl(override val type: ConeKotlinType) : ConeKotlinTypeProjectionOut()
 
-class ConeKotlinErrorType(val reason: String) : ConeKotlinType() {
-
-    override fun toString(): String {
-        return "<ERROR TYPE: $reason>"
-    }
-}
-
 class ConeAbbreviatedTypeImpl(
     override val abbreviationSymbol: ConeClassLikeSymbol,
     override val typeArguments: List<ConeKotlinTypeProjection>,
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt
index 7f0e3d452f2..b6f59a30ea0 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt
@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.fir.symbols.ConeClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.ConeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
 import org.jetbrains.kotlin.fir.types.*
-import org.jetbrains.kotlin.fir.types.impl.ConeKotlinErrorType
 import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.utils.Printer
@@ -453,7 +452,6 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
             is ConeTypeParameterType -> {
                 symbol.asString()
             }
-            else -> "Unsupported: $this"
         }
     }