diff --git a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirType.kt b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirType.kt
index 603a4c6e0a5..bc3bf7d7246 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirType.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirType.kt
@@ -11,9 +11,7 @@ import org.jetbrains.kotlin.types.Variance
 
 typealias CirTypeSignature = String
 
-sealed class CirType {
-    abstract val signature: CirTypeSignature
-}
+sealed class CirType
 
 /**
  * All attributes are read from the abbreviation type: [AbbreviatedType.abbreviation].
@@ -33,9 +31,6 @@ abstract class CirSimpleType : CirType(), CirHasVisibility {
     abstract val isDefinitelyNotNullType: Boolean
 }
 
-data class CirTypeProjection(val projectionKind: Variance, val isStarProjection: Boolean, val type: CirType)
+data class CirFlexibleType(val lowerBound: CirSimpleType, val upperBound: CirSimpleType) : CirType()
 
-data class CirFlexibleType(val lowerBound: CirSimpleType, val upperBound: CirSimpleType) : CirType() {
-    override val signature: CirTypeSignature
-        get() = lowerBound.signature
-}
+data class CirTypeProjection(val projectionKind: Variance, val isStarProjection: Boolean, val type: CirType)
diff --git a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirTypeFactory.kt b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirTypeFactory.kt
index 30e92bfaa9f..86ded8ab67c 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirTypeFactory.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirTypeFactory.kt
@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.descriptors.commonizer.cir.*
 import org.jetbrains.kotlin.descriptors.commonizer.cir.impl.CirSimpleTypeImpl
 import org.jetbrains.kotlin.descriptors.commonizer.utils.Interner
 import org.jetbrains.kotlin.descriptors.commonizer.utils.declarationDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.utils.signature
 import org.jetbrains.kotlin.types.*
 
 object CirTypeFactory {
@@ -41,8 +40,7 @@ object CirTypeFactory {
                 )
             },
             isMarkedNullable = abbreviation.isMarkedNullable,
-            isDefinitelyNotNullType = abbreviation.isDefinitelyNotNullType,
-            signature = source.signature
+            isDefinitelyNotNullType = abbreviation.isDefinitelyNotNullType
         )
     }
 
@@ -51,8 +49,7 @@ object CirTypeFactory {
         visibility: Visibility,
         arguments: List<CirTypeProjection>,
         isMarkedNullable: Boolean,
-        isDefinitelyNotNullType: Boolean,
-        signature: CirTypeSignature
+        isDefinitelyNotNullType: Boolean
     ): CirSimpleType {
         return interner.intern(
             CirSimpleTypeImpl(
@@ -60,8 +57,7 @@ object CirTypeFactory {
                 visibility = visibility,
                 arguments = arguments,
                 isMarkedNullable = isMarkedNullable,
-                isDefinitelyNotNullType = isDefinitelyNotNullType,
-                signature = signature
+                isDefinitelyNotNullType = isDefinitelyNotNullType
             )
         )
     }
diff --git a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/impl/CirSimpleTypeImpl.kt b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/impl/CirSimpleTypeImpl.kt
index 59469774f97..1b5c0e84f32 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/impl/CirSimpleTypeImpl.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/impl/CirSimpleTypeImpl.kt
@@ -15,8 +15,7 @@ data class CirSimpleTypeImpl(
     override val visibility: Visibility, // visibility of the classifier descriptor
     override val arguments: List<CirTypeProjection>,
     override val isMarkedNullable: Boolean,
-    override val isDefinitelyNotNullType: Boolean,
-    override val signature: CirTypeSignature
+    override val isDefinitelyNotNullType: Boolean
 ) : CirSimpleType() {
     // See also org.jetbrains.kotlin.types.KotlinType.cachedHashCode
     private var cachedHashCode = 0
@@ -26,7 +25,6 @@ data class CirSimpleTypeImpl(
         .appendHashCode(arguments)
         .appendHashCode(isMarkedNullable)
         .appendHashCode(isDefinitelyNotNullType)
-        .appendHashCode(signature)
 
     override fun hashCode(): Int {
         var currentHashCode = cachedHashCode
@@ -44,7 +42,6 @@ data class CirSimpleTypeImpl(
                     && classifierId == other.classifierId
                     && visibility == other.visibility
                     && arguments == other.arguments
-                    && signature == other.signature
                     && isDefinitelyNotNullType == other.isDefinitelyNotNullType
         }
         else -> false
diff --git a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/AnnotationsCommonizer.kt b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/AnnotationsCommonizer.kt
index 341bb33d41b..0fcac0afb83 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/AnnotationsCommonizer.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/AnnotationsCommonizer.kt
@@ -165,8 +165,7 @@ private class DeprecatedAnnotationCommonizer : Commonizer<CirAnnotation, CirAnno
             visibility = Visibilities.PUBLIC,
             arguments = emptyList(),
             isMarkedNullable = false,
-            isDefinitelyNotNullType = false,
-            signature = classId.asString()
+            isDefinitelyNotNullType = false
         )
 
         private fun CirAnnotation.getDeprecationMessage(): String? = constantValueArguments.getString(PROPERTY_NAME_MESSAGE)
diff --git a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt
index 9eaf447b126..db98541df25 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt
@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.descriptors.commonizer.core
 
 import org.jetbrains.kotlin.descriptors.commonizer.cir.CirType
-import org.jetbrains.kotlin.descriptors.commonizer.cir.CirTypeSignature
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.*
 import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.utils.internedClassId
@@ -93,10 +92,10 @@ internal class CommonizationVisitor(
             }
 
             // find out common (and commonized) supertypes
-            val supertypesMap: MutableMap<CirTypeSignature, CommonizedGroup<CirType>> = linkedMapOf() // preserve supertype order
+            val supertypesMap: MutableMap<CirType, CommonizedGroup<CirType>> = linkedMapOf() // preserve supertype order
             node.targetDeclarations.forEachIndexed { index, clazz ->
                 for (supertype in clazz!!.supertypes) {
-                    supertypesMap.getOrPut(supertype.signature) { CommonizedGroup(node.targetDeclarations.size) }[index] = supertype
+                    supertypesMap.getOrPut(supertype) { CommonizedGroup(node.targetDeclarations.size) }[index] = supertype
                 }
             }