diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/substitution/Substitutors.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/substitution/Substitutors.kt
index 2d498d16188..5fd020112d2 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/substitution/Substitutors.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/substitution/Substitutors.kt
@@ -13,9 +13,10 @@ import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.types.TypeApproximatorConfiguration
 import org.jetbrains.kotlin.types.model.TypeConstructorMarker
 import org.jetbrains.kotlin.types.model.TypeSubstitutorMarker
+import org.jetbrains.kotlin.types.model.TypeVariableMarker
 import org.jetbrains.kotlin.types.model.typeConstructor
 
-abstract class AbstractConeSubstitutor(private val typeContext: ConeTypeContext) : ConeSubstitutor() {
+abstract class AbstractConeSubstitutor(protected val typeContext: ConeTypeContext) : ConeSubstitutor() {
     private fun wrapProjection(old: ConeTypeProjection, newType: ConeKotlinType): ConeTypeProjection {
         return when (old) {
             is ConeStarProjection -> old
@@ -204,3 +205,27 @@ fun createTypeSubstitutorByTypeConstructor(map: Map<TypeConstructorMarker, ConeK
         }
     }
 }
+
+internal class TypeSubstitutorByTypeConstructor(
+    private val map: Map<TypeConstructorMarker, ConeKotlinType>,
+    context: ConeTypeContext
+) : AbstractConeSubstitutor(context), TypeSubstitutorMarker {
+    override fun substituteType(type: ConeKotlinType): ConeKotlinType? {
+        if (type !is ConeLookupTagBasedType && type !is ConeStubType) return null
+        val new = map[type.typeConstructor(typeContext)] ?: return null
+        return new.approximateIntegerLiteralType().updateNullabilityIfNeeded(type)?.withCombinedAttributesFrom(type, typeContext)
+    }
+}
+
+// Note: builder inference uses TypeSubstitutorByTypeConstructor for not fixed type substitution
+class NotFixedTypeToVariableSubstitutorForDelegateInference(
+    private val bindings: Map<TypeVariableMarker, ConeKotlinType>,
+    typeContext: ConeTypeContext
+) : AbstractConeSubstitutor(typeContext) {
+    override fun substituteType(type: ConeKotlinType): ConeKotlinType? {
+        if (type !is ConeStubType) return null
+        if (type.constructor.isTypeVariableInSubtyping) return null
+        return bindings[type.constructor.variable].updateNullabilityIfNeeded(type)
+    }
+}
+
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirBuilderInferenceSession.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirBuilderInferenceSession.kt
index 68c8136f96e..bc830a1f31e 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirBuilderInferenceSession.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirBuilderInferenceSession.kt
@@ -165,14 +165,14 @@ class FirBuilderInferenceSession(
     }
 
     private fun createNonFixedTypeToVariableSubstitutor(): ConeSubstitutor {
-        val ctx = components.session.typeContext
+        val typeContext = components.session.typeContext
 
         val bindings = mutableMapOf<TypeConstructorMarker, ConeKotlinType>()
         for ((variable, nonFixedType) in stubsForPostponedVariables) {
             bindings[nonFixedType.constructor] = variable.defaultType
         }
 
-        return ctx.typeSubstitutorByTypeConstructor(bindings)
+        return typeContext.typeSubstitutorByTypeConstructor(bindings)
     }
 
     private fun integrateConstraints(
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirDelegatedPropertyInferenceSession.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirDelegatedPropertyInferenceSession.kt
index 22b9b1bddde..7d684ff5f87 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirDelegatedPropertyInferenceSession.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirDelegatedPropertyInferenceSession.kt
@@ -10,9 +10,9 @@ import org.jetbrains.kotlin.fir.expressions.FirResolvable
 import org.jetbrains.kotlin.fir.expressions.FirStatement
 import org.jetbrains.kotlin.fir.resolve.calls.*
 import org.jetbrains.kotlin.fir.resolve.inference.model.ConeFixVariableConstraintPosition
-import org.jetbrains.kotlin.fir.resolve.substitution.AbstractConeSubstitutor
 import org.jetbrains.kotlin.fir.resolve.substitution.ChainedSubstitutor
 import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
+import org.jetbrains.kotlin.fir.resolve.substitution.NotFixedTypeToVariableSubstitutorForDelegateInference
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.resolve.calls.inference.NewConstraintSystem
 import org.jetbrains.kotlin.resolve.calls.inference.buildAbstractResultingSubstitutor
@@ -110,7 +110,7 @@ class FirDelegatedPropertyInferenceSession(
         completionMode: ConstraintSystemCompletionMode
     ): Map<ConeTypeVariableTypeConstructor, ConeKotlinType>? = null
 
-    private fun createNonFixedTypeToVariableSubstitutor(): ConeSubstitutor {
+    private fun createNonFixedTypeToVariableSubstitutor(): NotFixedTypeToVariableSubstitutorForDelegateInference {
         val typeContext = components.session.typeContext
 
         val bindings = mutableMapOf<TypeVariableMarker, ConeKotlinType>()
@@ -118,13 +118,7 @@ class FirDelegatedPropertyInferenceSession(
             bindings[synthetic] = variable.defaultType(typeContext) as ConeKotlinType
         }
 
-        return object : AbstractConeSubstitutor(typeContext) {
-            override fun substituteType(type: ConeKotlinType): ConeKotlinType? {
-                if (type !is ConeStubType) return null
-                if (type.constructor.isTypeVariableInSubtyping) return null
-                return bindings[type.constructor.variable].updateNullabilityIfNeeded(type)
-            }
-        }
+        return NotFixedTypeToVariableSubstitutorForDelegateInference(bindings, typeContext)
     }