diff --git a/analysis/analysis-api/testData/symbols/symbolByReference/javaMethodWithExternalNotNullAnnotation.txt b/analysis/analysis-api/testData/symbols/symbolByReference/javaMethodWithExternalNotNullAnnotation.txt
index 5e510a4ea57..23961486487 100644
--- a/analysis/analysis-api/testData/symbols/symbolByReference/javaMethodWithExternalNotNullAnnotation.txt
+++ b/analysis/analysis-api/testData/symbols/symbolByReference/javaMethodWithExternalNotNullAnnotation.txt
@@ -24,7 +24,7 @@ KtFunctionSymbol:
   receiverParameter: null
   returnType: KtFlexibleType:
     annotationsList: []
-    type: kotlin/String!
+    type: Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!
   symbolKind: CLASS_MEMBER
   typeParameters: []
   valueParameters: []
diff --git a/analysis/low-level-api-fir/testData/getOrBuildFir/wholeDeclaration/externalJavaAnnotation.txt b/analysis/low-level-api-fir/testData/getOrBuildFir/wholeDeclaration/externalJavaAnnotation.txt
index 418b8dfff60..5c1c881f2b9 100644
--- a/analysis/low-level-api-fir/testData/getOrBuildFir/wholeDeclaration/externalJavaAnnotation.txt
+++ b/analysis/low-level-api-fir/testData/getOrBuildFir/wholeDeclaration/externalJavaAnnotation.txt
@@ -3,12 +3,12 @@ FIR element: FirSimpleFunctionImpl
 FIR source kind: KtRealSourceElementKind
 
 FIR element rendered:
-public final [ResolvedTo(BODY_RESOLVE)] fun test(): R|kotlin/String!| {
+public final [ResolvedTo(BODY_RESOLVE)] fun test(): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!| {
     ^test R|/ClassWithExternalAnnotatedMembers.ClassWithExternalAnnotatedMembers|().R|/ClassWithExternalAnnotatedMembers.externalNotNullMethod|()
 }
 
 FIR FILE:
 FILE: [ResolvedTo(IMPORTS)] usage.kt
-    public final [ResolvedTo(BODY_RESOLVE)] fun test(): R|kotlin/String!| {
+    public final [ResolvedTo(BODY_RESOLVE)] fun test(): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!| {
         ^test R|/ClassWithExternalAnnotatedMembers.ClassWithExternalAnnotatedMembers|().R|/ClassWithExternalAnnotatedMembers.externalNotNullMethod|()
     }
\ No newline at end of file
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/NonNullNever.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/NonNullNever.fir.txt
index b743ae636b4..78e5c7b697a 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/NonNullNever.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/NonNullNever.fir.txt
@@ -5,7 +5,7 @@
 public open class NonNullNever : R|kotlin/Any| {
     @R|javax/annotation/Nonnull|(when = R|javax/annotation/meta/When.NEVER|) public open field field: R|kotlin/String?|
 
-    @R|MyNullable|() public open fun foo(@R|javax/annotation/Nonnull|(when = R|javax/annotation/meta/When.NEVER|) x: R|kotlin/String?|, @R|MyNullable|() y: R|kotlin/CharSequence!|): R|kotlin/String!|
+    @R|MyNullable|() public open fun foo(@R|javax/annotation/Nonnull|(when = R|javax/annotation/meta/When.NEVER|) x: R|kotlin/String?|, @R|MyNullable|() y: R|Enhanced for warning(kotlin/CharSequence?) kotlin/CharSequence!|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
     public constructor(): R|NonNullNever|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/FieldsAreNullable.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/FieldsAreNullable.fir.txt
index 37c3f7b1eec..6807769b95a 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/FieldsAreNullable.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/FieldsAreNullable.fir.txt
@@ -1,5 +1,5 @@
 @R|FieldsAreNullable|() public open class A : R|kotlin/Any| {
-    public open field field: R|kotlin/String!|
+    public open field field: R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
     @R|javax/annotation/Nonnull|() public open field nonNullField: R|@EnhancedNullability kotlin/String|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ForceFlexibility.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ForceFlexibility.fir.txt
index 365f314e6d9..b6cc02979e2 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ForceFlexibility.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ForceFlexibility.fir.txt
@@ -1,5 +1,5 @@
 @R|spr/NonNullApi|() public open class A : R|kotlin/Any| {
-    public open fun foo(x: R|kotlin/String!|, @R|spr/Nullable|() y: R|kotlin/CharSequence!|): R|kotlin/String!|
+    public open fun foo(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|spr/Nullable|() y: R|Enhanced for warning(kotlin/CharSequence?) kotlin/CharSequence!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
     @R|spr/ForceFlexibility|() public open fun bar(x: R|kotlin/String!|, @R|javax/annotation/Nonnull|() y: R|@EnhancedNullability kotlin/CharSequence|): R|kotlin/String!|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/NullabilityFromOverridden.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/NullabilityFromOverridden.fir.txt
index 7ab662a7684..345fcc1a19c 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/NullabilityFromOverridden.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/NullabilityFromOverridden.fir.txt
@@ -1,55 +1,55 @@
 @R|NonNullApi|() public open class A : R|kotlin/Any| {
-    public open fun foo1(x: R|kotlin/String!|): R|kotlin/String!|
+    public open fun foo1(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    public open fun foo2(x: R|kotlin/String!|): R|kotlin/String!|
+    public open fun foo2(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    public open fun foo3(x: R|kotlin/String!|): R|kotlin/String!|
+    public open fun foo3(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
     @R|javax/annotation/Nullable|() public open fun bar1(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/String?|
 
     @R|javax/annotation/Nullable|() public open fun bar2(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/String?|
 
-    public open fun baz(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|kotlin/String!|
+    public open fun baz(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
     public constructor(): R|A|
 
 }
 @R|NonNullApi|() public abstract interface AInt : R|kotlin/Any| {
-    public abstract fun foo1(x: R|kotlin/String!|): R|kotlin/CharSequence!|
+    public abstract fun foo1(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/CharSequence) kotlin/CharSequence!|
 
-    public abstract fun foo2(x: R|kotlin/String!|): R|kotlin/CharSequence!|
+    public abstract fun foo2(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/CharSequence) kotlin/CharSequence!|
 
-    public abstract fun foo3(x: R|kotlin/String!|): R|kotlin/CharSequence!|
+    public abstract fun foo3(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/CharSequence) kotlin/CharSequence!|
 
     @R|javax/annotation/Nullable|() public abstract fun bar1(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/CharSequence?|
 
     @R|javax/annotation/Nullable|() public abstract fun bar2(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/CharSequence?|
 
-    public abstract fun baz(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|kotlin/CharSequence!|
+    public abstract fun baz(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|Enhanced for warning(@EnhancedNullability kotlin/CharSequence) kotlin/CharSequence!|
 
 }
 @R|NullableApi|() public open class B : R|A|, R|AInt| {
-    public open fun foo1(x: R|kotlin/String!|): R|kotlin/String!|
+    public open fun foo1(x: R|Enhanced for warning(kotlin/String?) kotlin/String!|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
     @R|javax/annotation/Nonnull|() public open fun foo2(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 
     public open fun bar1(x: R|kotlin/String?|): R|kotlin/String?|
 
-    public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|kotlin/String!|
+    public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
     public constructor(): R|B|
 
 }
 @R|NonNullApi|() public open class C : R|A|, R|AInt| {
-    public open fun foo1(x: R|kotlin/String!|): R|kotlin/String!|
+    public open fun foo1(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    public open fun foo2(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|kotlin/String!|
+    public open fun foo2(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
     public open fun bar1(x: R|kotlin/String?|): R|kotlin/String?|
 
     @R|javax/annotation/Nullable|() public open fun bar2(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/String?|
 
-    public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|kotlin/String!|
+    public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
     public constructor(): R|C|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/OverridingDefaultQualifier.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/OverridingDefaultQualifier.fir.txt
index 5641a47cc44..3223b5adad3 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/OverridingDefaultQualifier.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/OverridingDefaultQualifier.fir.txt
@@ -1,24 +1,24 @@
 @R|NonNullApi|() public open class A : R|kotlin/Any| {
-    public open field field: R|kotlin/String!|
+    public open field field: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    public open fun foo(x: R|kotlin/String!|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
+    public open fun foo(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    @R|NullableApi|() public open fun foobar(x: R|kotlin/String!|, @R|NonNullApi|() y: R|kotlin/CharSequence!|): R|kotlin/String!|
+    @R|NullableApi|() public open fun foobar(x: R|Enhanced for warning(kotlin/String?) kotlin/String!|, @R|NonNullApi|() y: R|Enhanced for warning(@EnhancedNullability kotlin/CharSequence) kotlin/CharSequence!|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
-    public open fun bar(): R|kotlin/String!|
+    public open fun bar(): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
     @R|javax/annotation/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<kotlin/String!>?, kotlin/collections/List<kotlin/String!>?>|
 
     public constructor(): R|A|
 
     @R|NullableApi|() public open inner class B : R|kotlin/Any| {
-        public open field field: R|kotlin/String!|
+        public open field field: R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
-        public open fun foo(x: R|kotlin/String!|, @R|javax/annotation/Nonnull|() y: R|@EnhancedNullability kotlin/CharSequence|): R|kotlin/String!|
+        public open fun foo(x: R|Enhanced for warning(kotlin/String?) kotlin/String!|, @R|javax/annotation/Nonnull|() y: R|@EnhancedNullability kotlin/CharSequence|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
-        @R|NonNullApi|() public open fun foobar(x: R|kotlin/String!|, @R|NullableApi|() y: R|kotlin/CharSequence!|): R|kotlin/String!|
+        @R|NonNullApi|() public open fun foobar(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|NullableApi|() y: R|Enhanced for warning(kotlin/CharSequence?) kotlin/CharSequence!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-        public open fun bar(): R|kotlin/String!|
+        public open fun bar(): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
         @R|javax/annotation/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<kotlin/String!>?, kotlin/collections/List<kotlin/String!>?>|
 
@@ -26,13 +26,13 @@
 
     }
     @R|FieldsAreNullable|() public open inner class C : R|kotlin/Any| {
-        public open field field: R|kotlin/String!|
+        public open field field: R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
-        public open fun foo(x: R|kotlin/String!|, @R|javax/annotation/Nullable|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
+        public open fun foo(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|javax/annotation/Nullable|() y: R|kotlin/CharSequence?|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-        @R|NullableApi|() public open fun foobar(x: R|kotlin/String!|, @R|javax/annotation/Nullable|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
+        @R|NullableApi|() public open fun foobar(x: R|Enhanced for warning(kotlin/String?) kotlin/String!|, @R|javax/annotation/Nullable|() y: R|kotlin/CharSequence?|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
 
-        public open fun bar(): R|kotlin/String!|
+        public open fun bar(): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
         @R|javax/annotation/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<kotlin/String!>?, kotlin/collections/List<kotlin/String!>?>|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefault.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefault.fir.txt
index cf9c73e7660..f28f4a2f51c 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefault.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefault.fir.txt
@@ -1,7 +1,7 @@
 @R|javax/annotation/ParametersAreNonnullByDefault|() public open class A : R|kotlin/Any| {
     @R|javax/annotation/Nullable|() public open field field: R|kotlin/String?|
 
-    public open fun foo(q: R|kotlin/String!|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
+    public open fun foo(q: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefaultPackage.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefaultPackage.fir.txt
index cbc09931bdc..ed53b80d7d4 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefaultPackage.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefaultPackage.fir.txt
@@ -1,7 +1,7 @@
 public open class A : R|kotlin/Any| {
     @R|javax/annotation/Nullable|() public open field field: R|kotlin/String?|
 
-    public open fun foo(q: R|kotlin/String!|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
+    public open fun foo(q: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|kotlin/String!|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullable.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullable.fir.txt
index 4aa8f9a5638..893203d60a2 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullable.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullable.fir.txt
@@ -1,11 +1,11 @@
 @R|spr/NonNullApi|() public open class A : R|kotlin/Any| {
     public open field field: R|kotlin/String!|
 
-    public open fun foo(x: R|kotlin/String!|, @R|spr/Nullable|() y: R|kotlin/CharSequence!|): R|kotlin/String!|
+    public open fun foo(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|spr/Nullable|() y: R|Enhanced for warning(kotlin/CharSequence?) kotlin/CharSequence!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    public open fun bar(): R|kotlin/String!|
+    public open fun bar(): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    @R|spr/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<kotlin/String!>, kotlin/collections/List<kotlin/String!>?>|
+    @R|spr/Nullable|() public open fun baz(): R|ft<Enhanced for warning(kotlin/collections/MutableList<kotlin/String!>?) kotlin/collections/MutableList<kotlin/String!>, kotlin/collections/List<kotlin/String!>?>|
 
     public constructor(): R|A|
 
diff --git a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullablePackage.fir.txt b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullablePackage.fir.txt
index 2249215624a..26574ce5a9e 100644
--- a/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullablePackage.fir.txt
+++ b/compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullablePackage.fir.txt
@@ -1,11 +1,11 @@
 public open class A : R|kotlin/Any| {
     public open field field: R|kotlin/String!|
 
-    public open fun foo(x: R|kotlin/String!|, @R|spr/Nullable|() y: R|kotlin/CharSequence!|): R|kotlin/String!|
+    public open fun foo(x: R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|, @R|spr/Nullable|() y: R|Enhanced for warning(kotlin/CharSequence?) kotlin/CharSequence!|): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    public open fun bar(): R|kotlin/String!|
+    public open fun bar(): R|Enhanced for warning(@EnhancedNullability kotlin/String) kotlin/String!|
 
-    @R|spr/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<kotlin/String!>, kotlin/collections/List<kotlin/String!>?>|
+    @R|spr/Nullable|() public open fun baz(): R|ft<Enhanced for warning(kotlin/collections/MutableList<kotlin/String!>?) kotlin/collections/MutableList<kotlin/String!>, kotlin/collections/List<kotlin/String!>?>|
 
     public constructor(): R|test/A|
 
diff --git a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/EnhancedTypeForWarningAttribute.kt b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/EnhancedTypeForWarningAttribute.kt
new file mode 100644
index 00000000000..58b43a95f9f
--- /dev/null
+++ b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/EnhancedTypeForWarningAttribute.kt
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.java.enhancement
+
+import org.jetbrains.kotlin.fir.types.ConeAttributeWithConeType
+import org.jetbrains.kotlin.fir.types.ConeAttributes
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.renderForDebugging
+import kotlin.reflect.KClass
+
+class EnhancedTypeForWarningAttribute(
+    override val coneType: ConeKotlinType,
+) : ConeAttributeWithConeType<EnhancedTypeForWarningAttribute>() {
+    override fun union(other: EnhancedTypeForWarningAttribute?): EnhancedTypeForWarningAttribute? = null
+    override fun intersect(other: EnhancedTypeForWarningAttribute?): EnhancedTypeForWarningAttribute? = null
+    override fun add(other: EnhancedTypeForWarningAttribute?): EnhancedTypeForWarningAttribute = other ?: this
+    override fun isSubtypeOf(other: EnhancedTypeForWarningAttribute?): Boolean = true
+    override fun toString(): String = "Enhanced for warning(${coneType.renderForDebugging()})"
+    override fun copyWith(newType: ConeKotlinType): EnhancedTypeForWarningAttribute = EnhancedTypeForWarningAttribute(newType)
+
+    override val key: KClass<out EnhancedTypeForWarningAttribute>
+        get() = EnhancedTypeForWarningAttribute::class
+
+    override val keepInInferredDeclarationType: Boolean
+        get() = true
+}
+
+val ConeAttributes.enhancedTypeForWarning: EnhancedTypeForWarningAttribute? by ConeAttributes.attributeAccessor<EnhancedTypeForWarningAttribute>()
+
+val ConeKotlinType.enhancedTypeForWarning: ConeKotlinType?
+    get() = attributes.enhancedTypeForWarning?.coneType
\ No newline at end of file
diff --git a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt
index 131b9722839..4fed763b7ee 100644
--- a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt
+++ b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt
@@ -40,14 +40,10 @@ private fun ConeKotlinType.enhanceConeKotlinType(
 ): ConeKotlinType? {
     return when (this) {
         is ConeFlexibleType -> {
-            // Currently, the warnings are left unsupported in K2 (see KT-57307)
-            // But modulo information for warnings, we reproduce the K1 behavior: if head type qualifier is for warnings, we totally ignore
+            // We reproduce the K1 behavior: if head type qualifier is for warnings, we totally ignore
             // enhancement on its arguments, too (see JavaTypeEnhancement.enhancePossiblyFlexible).
             // It's not totally correct, but tolerable since we would like to avoid excessive breaking changes and the warnings should be
             // anyway reported.
-            // TODO: support not loosing information for warnings here, too
-            if (qualifiers(index).isNullabilityQualifierForWarning) return null
-
             val lowerResult = lowerBound.enhanceInflexibleType(
                 session, TypeComponentPosition.FLEXIBLE_LOWER, qualifiers, index, subtreeSizes
             )
@@ -96,9 +92,36 @@ private fun ConeSimpleKotlinType.enhanceInflexibleType(
     val effectiveQualifiers = qualifiers(index)
     val enhancedTag = lookupTag.enhanceMutability(effectiveQualifiers, position)
 
-    // TODO: implement warnings (see KT-57307)
-    val nullabilityFromQualifiers = effectiveQualifiers.nullability
-        .takeIf { shouldEnhance && !effectiveQualifiers.isNullabilityQualifierForWarning }
+    val nullabilityFromQualifiers = effectiveQualifiers.nullability.takeIf { shouldEnhance }
+
+    val enhanced = enhanceInflexibleType(
+        session,
+        qualifiers,
+        index,
+        subtreeSizes,
+        isFromDefinitelyNotNullType,
+        effectiveQualifiers.definitelyNotNull,
+        nullabilityFromQualifiers,
+        enhancedTag
+    )
+
+    return if (effectiveQualifiers.isNullabilityQualifierForWarning && enhanced != null) {
+        this.withAttributes(attributes.plus(EnhancedTypeForWarningAttribute(enhanced)))
+    } else {
+        enhanced
+    }
+}
+
+private fun ConeLookupTagBasedType.enhanceInflexibleType(
+    session: FirSession,
+    qualifiers: IndexedJavaTypeQualifiers,
+    index: Int,
+    subtreeSizes: List<Int>,
+    isFromDefinitelyNotNullType: Boolean,
+    isDefinitelyNotNull: Boolean,
+    nullabilityFromQualifiers: NullabilityQualifier?,
+    enhancedTag: ConeClassifierLookupTag,
+): ConeSimpleKotlinType? {
     val enhancedIsNullable = when (nullabilityFromQualifiers) {
         NullabilityQualifier.NULLABLE -> true
         NullabilityQualifier.NOT_NULL -> false
@@ -126,7 +149,7 @@ private fun ConeSimpleKotlinType.enhanceInflexibleType(
     val mergedArguments = Array(typeArguments.size) { enhancedArguments[it] ?: typeArguments[it] }
     val mergedAttributes = if (shouldAddAttribute) attributes + CompilerConeAttributes.EnhancedNullability else attributes
     val enhancedType = enhancedTag.constructType(mergedArguments, enhancedIsNullable, mergedAttributes)
-    return if (effectiveQualifiers.definitelyNotNull || (isFromDefinitelyNotNullType && nullabilityFromQualifiers == null))
+    return if (isDefinitelyNotNull || (isFromDefinitelyNotNullType && nullabilityFromQualifiers == null))
         ConeDefinitelyNotNullType.create(enhancedType, session.typeContext) ?: enhancedType
     else
         enhancedType