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 14646602f84..86bfa8d6eea 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
@@ -29,13 +29,13 @@
 
 }
 @R|NullableApi|() public open class B : R|A|, R|AInt| {
-    public open fun foo1(x: R|Enhanced for warning(kotlin/String?) kotlin/String!|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
+    public open fun foo1(x: R|kotlin/String!|): R|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|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/String?|
 
-    public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|Enhanced for warning(kotlin/String?) kotlin/String!|
+    public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|kotlin/String!|
 
     public constructor(): R|B|
 
diff --git a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/SignatureEnhancement.kt b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/SignatureEnhancement.kt
index 86b215a0700..4aab1c4758f 100644
--- a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/SignatureEnhancement.kt
+++ b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/SignatureEnhancement.kt
@@ -891,7 +891,7 @@ private class EnhancementSignatureParts(
         get() = ((this as? ConeLookupTagBasedType)?.lookupTag as? ConeClassLikeLookupTag)?.classId?.asSingleFqName()?.toUnsafe()
 
     override val KotlinTypeMarker.enhancedForWarnings: KotlinTypeMarker?
-        get() = null // TODO: implement enhancement for warnings
+        get() = (this as ConeKotlinType).enhancedTypeForWarning
 
     override fun KotlinTypeMarker.isEqual(other: KotlinTypeMarker): Boolean =
         AbstractTypeChecker.equalTypes(session.typeContext, this, other)
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 a1376c6e76f..49639eabe28 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
@@ -8,7 +8,9 @@ package org.jetbrains.kotlin.fir.java.enhancement
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirClassLikeDeclaration
 import org.jetbrains.kotlin.fir.languageVersionSettings
+import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.symbols.ConeClassifierLookupTag
 import org.jetbrains.kotlin.fir.types.*
@@ -160,17 +162,31 @@ private fun ConeLookupTagBasedType.enhanceInflexibleType(
     }
 
     var globalArgIndex = index + 1
-    val enhancedArguments = typeArguments.map { arg ->
-        val argIndex = globalArgIndex.also { globalArgIndex += subtreeSizes[it] }
-        arg.type?.enhanceConeKotlinType(session, qualifiers, argIndex, subtreeSizes, convertErrorsToWarnings = convertNestedErrorsToWarnings)
-            ?.let {
-                when (arg.kind) {
-                    ProjectionKind.IN -> ConeKotlinTypeProjectionIn(it)
-                    ProjectionKind.OUT -> ConeKotlinTypeProjectionOut(it)
-                    ProjectionKind.STAR -> ConeStarProjection
-                    ProjectionKind.INVARIANT -> it
-                }
+    val enhancedArguments = typeArguments.mapIndexed { currentArgLocalIndex, arg ->
+        val currentArgGlobalIndex = globalArgIndex.also { globalArgIndex += subtreeSizes[it] }
+        if (arg.type == null && qualifiers(currentArgGlobalIndex).nullability == NullabilityQualifier.FORCE_FLEXIBILITY) {
+            // Given `C<T extends @Nullable V>`, unannotated `C<?>` is `C<out (V..V?)>`.
+            val typeParameters = (this.lookupTag.toSymbol(session)?.fir as? FirClassLikeDeclaration)?.typeParameters
+            if (typeParameters != null) {
+                val bound = typeParameters[currentArgLocalIndex].symbol.fir.bounds.first().coneType
+                return@mapIndexed ConeKotlinTypeProjectionOut(
+                    ConeFlexibleType(
+                        bound.lowerBoundIfFlexible().withNullability(ConeNullability.NOT_NULL, session.typeContext),
+                        bound.upperBoundIfFlexible().withNullability(ConeNullability.NULLABLE, session.typeContext)
+                    )
+                )
             }
+        }
+        arg.type?.enhanceConeKotlinType(
+            session, qualifiers, currentArgGlobalIndex, subtreeSizes, convertErrorsToWarnings = convertNestedErrorsToWarnings
+        )?.let {
+            when (arg.kind) {
+                ProjectionKind.IN -> ConeKotlinTypeProjectionIn(it)
+                ProjectionKind.OUT -> ConeKotlinTypeProjectionOut(it)
+                ProjectionKind.STAR -> ConeStarProjection
+                ProjectionKind.INVARIANT -> it
+            }
+        }
     }
 
     val shouldAddAttribute = nullabilityFromQualifiers == NullabilityQualifier.NOT_NULL && !hasEnhancedNullability
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.fir.kt
deleted file mode 100644
index b5be33deeba..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.fir.kt
+++ /dev/null
@@ -1,34 +0,0 @@
-// FILE: NullnessUnspecifiedTypeParameter.java
-import org.jspecify.annotations.*;
-
-@NullMarked
-public class NullnessUnspecifiedTypeParameter<T> {
-    public void foo(T t) {}
-
-    public void bar(Test s, T t) {} // t should not become not nullable
-}
-
-// FILE: Test.java
-public class Test {}
-
-// FILE: main.kt
-// jspecify_nullness_mismatch
-fun main(a1: NullnessUnspecifiedTypeParameter<Any>, a2: NullnessUnspecifiedTypeParameter<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, x: Test): Unit {
-    // jspecify_nullness_mismatch
-    a1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.foo(1)
-
-    a2.foo(null)
-    a2.foo(1)
-
-    // jspecify_nullness_mismatch, jspecify_nullness_mismatch
-    a1.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    // jspecify_nullness_mismatch
-    a1.bar(x, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.bar(x, 1)
-
-    // jspecify_nullness_mismatch
-    a2.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, null)
-    a2.bar(x, null)
-    a2.bar(x, 1)
-}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.kt
index aad5c65b3ae..8dc05e40732 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/default.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: NullnessUnspecifiedTypeParameter.java
 import org.jspecify.annotations.*;
 
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.fir.kt
deleted file mode 100644
index ae0e41e2640..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.fir.kt
+++ /dev/null
@@ -1,20 +0,0 @@
-// JSPECIFY_STATE: strict
-// FILE: Box.java
-
-import org.jspecify.annotations.*;
-
-@NullMarked
-public class Box<V extends @Nullable Object> {
-    public static <V extends @Nullable Object> Box<V> make() {
-        return new Box<>();
-    }
-}
-
-// FILE: Util.java
-public final class Util {
-    public Box<?> boxId(Box<?> box) { return box; }
-}
-
-// FILE: a.kt
-fun foo(u: Util) =
-    u.boxId(Box.<!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>make<!>())
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.kt
index 3016e74a14c..c3577c5bd39 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NullMarkedWithStarType.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: strict
 // FILE: Box.java
 
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.fir.kt
deleted file mode 100644
index 6313fc4f6c9..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.fir.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-// JSPECIFY_STATE: strict
-// !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
-
-// FILE: J1.java
-import org.jspecify.annotations.*;
-
-@NullMarked
-public interface J1<T extends @Nullable Object> {
-    T foo();
-}
-
-// FILE: J2.java
-public interface J2 {
-    J1<?> bar();
-}
-
-// FILE: main.kt
-fun baz(j2: J2): Any = <!RETURN_TYPE_MISMATCH!>j2.bar().foo()<!> // Any..Any?
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt
index 9b7032da0f6..2d98b53785c 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: strict
 // !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
 
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.fir.kt
deleted file mode 100644
index 6c416d2004a..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.fir.kt
+++ /dev/null
@@ -1,20 +0,0 @@
-// JSPECIFY_STATE: warn
-// FILE: Box.java
-
-import org.jspecify.annotations.*;
-
-@NullMarked
-public class Box<V extends @Nullable Object> {
-    public static <V extends @Nullable Object> Box<V> make() {
-        return new Box<>();
-    }
-}
-
-// FILE: Util.java
-public final class Util {
-    public Box<?> boxId(Box<?> box) { return box; }
-}
-
-// FILE: a.kt
-fun foo(u: Util) =
-    u.boxId(Box.<!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>make<!>())
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.kt
index b402eb0f232..cc3ac57fac7 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullMarkedWithStarType.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: warn
 // FILE: Box.java
 
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.fir.kt
deleted file mode 100644
index ea7fcb7f579..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.fir.kt
+++ /dev/null
@@ -1,35 +0,0 @@
-// JSPECIFY_STATE: warn
-// FILE: NullnessUnspecifiedTypeParameter.java
-import org.jspecify.annotations.*;
-
-@NullMarked
-public class NullnessUnspecifiedTypeParameter<T> {
-    public void foo(T t) {}
-
-    public void bar(Test s, T t) {} // t should not become not nullable
-}
-
-// FILE: Test.java
-public class Test {}
-
-// FILE: main.kt
-// jspecify_nullness_mismatch
-fun main(a1: NullnessUnspecifiedTypeParameter<Any>, a2: NullnessUnspecifiedTypeParameter<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, x: Test): Unit {
-    // jspecify_nullness_mismatch
-    a1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.foo(1)
-
-    a2.foo(null)
-    a2.foo(1)
-
-    // jspecify_nullness_mismatch, jspecify_nullness_mismatch
-    a1.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    // jspecify_nullness_mismatch
-    a1.bar(x, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.bar(x, 1)
-
-    // jspecify_nullness_mismatch
-    a2.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, null)
-    a2.bar(x, null)
-    a2.bar(x, 1)
-}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.kt
index 0cf04e2b781..a9ca13c142b 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NullnessUnspecifiedTypeParameter.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: warn
 // FILE: NullnessUnspecifiedTypeParameter.java
 import org.jspecify.annotations.*;
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/SelfType.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/SelfType.fir.kt
index 8b1fe789cd3..be27c256d37 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/SelfType.fir.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/SelfType.fir.kt
@@ -40,15 +40,18 @@ public class CKN extends C<@Nullable CK> {}
 // FILE: main.kt
 fun main(ak: AK, akn: AKN, bk: BK, ck: CK, ckn: CKN): Unit {
     ak.foo(ak)
-    ak.foo(null)
+    // jspecify_nullness_mismatch
+    ak.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
 
     akn.foo(null) // the corresponding warning/error is present on the Java side
 
     bk.foo(bk)
-    bk.foo(null)
+    // jspecify_nullness_mismatch
+    bk.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
 
     ck.foo(ck)
-    ck.foo(null)
+    // jspecify_nullness_mismatch
+    ck.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
 
     ckn.foo(null) // the corresponding warning/error is present on the Java side
 }
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.fir.kt
index c40003cdce9..40f7802a060 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.fir.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.fir.kt
@@ -23,19 +23,24 @@ public class Test {}
 // jspecify_nullness_mismatch, jspecify_nullness_mismatch
 fun <T : Test> main(a1: A<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, a2: A<Test>, b1: B<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, b2: B<Test>, x: T): Unit {
     a1.foo(null)
-    a1.bar<T?>(null)
+    // jspecify_nullness_mismatch
+    a1.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     a1.bar<T>(x)
 
     a2.foo(null)
-    a2.bar<T?>(null)
+    // jspecify_nullness_mismatch
+    a2.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     a2.bar<T>(x)
 
-    b1.foo(null)
-    b1.bar<T?>(null)
+    // jspecify_nullness_mismatch
+    b1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
+    // jspecify_nullness_mismatch
+    b1.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     b1.bar<T>(x)
 
     // jspecify_nullness_mismatch
     b2.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    b2.bar<T?>(null)
+    // jspecify_nullness_mismatch
+    b2.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     b2.bar<T>(x)
 }
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.fir.kt
deleted file mode 100644
index 930bdf0bac8..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.fir.kt
+++ /dev/null
@@ -1,36 +0,0 @@
-// FILE: NullnessUnspecifiedTypeParameter.java
-import org.jspecify.nullness.*;
-
-@NullMarked
-public class NullnessUnspecifiedTypeParameter<T> {
-    public void foo(T t) {}
-
-    public void bar(Test s, T t) {} // t should not become not nullable
-}
-
-// FILE: Test.java
-public class Test {}
-
-// FILE: main.kt
-// jspecify_nullness_mismatch
-fun main(a1: NullnessUnspecifiedTypeParameter<Any>, a2: NullnessUnspecifiedTypeParameter<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, x: Test): Unit {
-    // jspecify_nullness_mismatch
-    a1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.foo(1)
-
-    // jspecify_nullness_mismatch
-    a2.foo(null)
-    a2.foo(1)
-
-    // jspecify_nullness_mismatch, jspecify_nullness_mismatch
-    a1.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    // jspecify_nullness_mismatch
-    a1.bar(x, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.bar(x, 1)
-
-    // jspecify_nullness_mismatch, jspecify_nullness_mismatch
-    a2.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, null)
-    // jspecify_nullness_mismatch
-    a2.bar(x, null)
-    a2.bar(x, 1)
-}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.kt
index 7b05a230ea9..8181702a4e9 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/default.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: NullnessUnspecifiedTypeParameter.java
 import org.jspecify.nullness.*;
 
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.fir.kt
deleted file mode 100644
index f78aaad678d..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.fir.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-// JSPECIFY_STATE: strict
-// !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
-
-// FILE: J1.java
-import org.jspecify.nullness.*;
-
-@NullMarked
-public interface J1<T extends @Nullable Object> {
-    T foo();
-}
-
-// FILE: J2.java
-public interface J2 {
-    J1<?> bar();
-}
-
-// FILE: main.kt
-fun baz(j2: J2): Any = <!RETURN_TYPE_MISMATCH!>j2.bar().foo()<!> // Any..Any?
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.kt
index 53881e2a111..52b0f9ac36a 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/strictMode/UnannotatedWildcard.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: strict
 // !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
 
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.fir.kt
deleted file mode 100644
index e36c47ac722..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.fir.kt
+++ /dev/null
@@ -1,37 +0,0 @@
-// JSPECIFY_STATE: warn
-// FILE: NullnessUnspecifiedTypeParameter.java
-import org.jspecify.nullness.*;
-
-@NullMarked
-public class NullnessUnspecifiedTypeParameter<T> {
-    public void foo(T t) {}
-
-    public void bar(Test s, T t) {} // t should not become not nullable
-}
-
-// FILE: Test.java
-public class Test {}
-
-// FILE: main.kt
-// jspecify_nullness_mismatch
-fun main(a1: NullnessUnspecifiedTypeParameter<Any>, a2: NullnessUnspecifiedTypeParameter<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, x: Test): Unit {
-    // jspecify_nullness_mismatch
-    a1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.foo(1)
-
-    // jspecify_nullness_mismatch
-    a2.foo(null)
-    a2.foo(1)
-
-    // jspecify_nullness_mismatch, jspecify_nullness_mismatch
-    a1.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    // jspecify_nullness_mismatch
-    a1.bar(x, <!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
-    a1.bar(x, 1)
-
-    // jspecify_nullness_mismatch, jspecify_nullness_mismatch
-    a2.bar(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>, null)
-    // jspecify_nullness_mismatch
-    a2.bar(x, null)
-    a2.bar(x, 1)
-}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.kt
index a3154623f08..fb154eeb38e 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/NullnessUnspecifiedTypeParameter.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JSPECIFY_STATE: warn
 // FILE: NullnessUnspecifiedTypeParameter.java
 import org.jspecify.nullness.*;
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/SelfType.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/SelfType.fir.kt
index a24dae1365e..ce78cab1543 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/SelfType.fir.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/SelfType.fir.kt
@@ -41,17 +41,17 @@ public class CKN extends C<@Nullable CK> {}
 fun main(ak: AK, akn: AKN, bk: BK, ck: CK, ckn: CKN): Unit {
     ak.foo(ak)
     // jspecify_nullness_mismatch
-    ak.foo(null)
+    ak.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
 
     akn.foo(null) // the corresponding warning/error is present on the Java side
 
     bk.foo(bk)
     // jspecify_nullness_mismatch
-    bk.foo(null)
+    bk.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
 
     ck.foo(ck)
     // jspecify_nullness_mismatch
-    ck.foo(null)
+    ck.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
 
     ckn.foo(null) // the corresponding warning/error is present on the Java side
 }
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/TypeParameterBounds.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/TypeParameterBounds.fir.kt
index ad09dacfb11..f20d372e6a4 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/TypeParameterBounds.fir.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecifyOld/warnMode/TypeParameterBounds.fir.kt
@@ -24,23 +24,23 @@ public class Test {}
 fun <T : Test> main(a1: A<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, a2: A<Test>, b1: B<<!UPPER_BOUND_VIOLATED_BASED_ON_JAVA_ANNOTATIONS!>Any?<!>>, b2: B<Test>, x: T): Unit {
     a1.foo(null)
     // jspecify_nullness_mismatch
-    a1.bar<T?>(null)
+    a1.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     a1.bar<T>(x)
 
     a2.foo(null)
     // jspecify_nullness_mismatch
-    a2.bar<T?>(null)
+    a2.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     a2.bar<T>(x)
 
     // jspecify_nullness_mismatch
-    b1.foo(null)
+    b1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     // jspecify_nullness_mismatch
-    b1.bar<T?>(null)
+    b1.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     b1.bar<T>(x)
 
     // jspecify_nullness_mismatch
     b2.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     // jspecify_nullness_mismatch
-    b2.bar<T?>(null)
+    b2.bar<T?>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     b2.bar<T>(x)
 }
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.fir.kt
deleted file mode 100644
index afdbdfeabd8..00000000000
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.fir.kt
+++ /dev/null
@@ -1,152 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
-// JSR305_GLOBAL_REPORT: warn
-
-// FILE: NonNullApi.java
-import java.lang.annotation.Documented;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-import javax.annotation.Nonnull;
-import javax.annotation.meta.TypeQualifierDefault;
-
-@Target(ElementType.TYPE)
-@Retention(RetentionPolicy.RUNTIME)
-@Documented
-@Nonnull
-@TypeQualifierDefault({ElementType.METHOD, ElementType.PARAMETER, ElementType.FIELD})
-public @interface NonNullApi {
-}
-
-// FILE: NullableApi.java
-import java.lang.annotation.Documented;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-import javax.annotation.CheckForNull;
-import javax.annotation.meta.TypeQualifierDefault;
-
-@Target(ElementType.TYPE)
-@Retention(RetentionPolicy.RUNTIME)
-@Documented
-@CheckForNull
-@TypeQualifierDefault({ElementType.METHOD, ElementType.PARAMETER, ElementType.FIELD})
-public @interface NullableApi {
-}
-
-// FILE: A.java
-import javax.annotation.CheckForNull;
-import javax.annotation.Nullable;
-import javax.annotation.Nonnull;
-
-@NonNullApi
-public class A {
-    public String foo1(String x) { return ""; }
-    public String foo2(String x) { return ""; }
-    public String foo3(String x) { return ""; }
-
-
-    @Nullable
-    public String bar1(@Nullable String x) { return ""; }
-    @Nullable
-    public String bar2(@Nullable String x) { return ""; }
-
-    public String baz(@Nonnull String x) { return ""; }
-}
-
-// FILE: AInt.java
-import javax.annotation.CheckForNull;
-import javax.annotation.Nullable;
-import javax.annotation.Nonnull;
-
-@NonNullApi
-public interface AInt {
-    public CharSequence foo1(String x);
-    public CharSequence foo2(String x);
-    public CharSequence foo3(String x);
-
-
-    @Nullable
-    public CharSequence bar1(@Nullable String x);
-    @Nullable
-    public CharSequence bar2(@Nullable String x);
-
-    public CharSequence baz(@Nonnull String x);
-}
-
-
-// FILE: B.java
-import javax.annotation.CheckForNull;
-import javax.annotation.Nullable;
-import javax.annotation.Nonnull;
-
-@NullableApi
-public class B extends A implements AInt {
-    // conflicts
-    public String foo1(String x) { return ""; }
-
-    // no conflicts
-    @Nonnull
-    public String foo2(@Nonnull String x) { return ""; }
-
-    // fake override for foo3 shouldn't have any conflicts
-
-    // no conflicts
-    public String bar1(String x) { return ""; }
-
-    // conflicts
-    public String baz(String x) { return ""; }
-}
-
-// FILE: C.java
-import javax.annotation.CheckForNull;
-import javax.annotation.Nullable;
-import javax.annotation.Nonnull;
-
-@NonNullApi
-public class C extends A implements AInt {
-    // no conflicts
-    public String foo1(String x) { return ""; }
-
-    // no conflicts
-    public String foo2(@Nonnull String x) { return ""; }
-
-    // fake override for foo3 shouldn't have any conflicts
-
-    // no conflicts, covariant override
-    public String bar1(String x) { return ""; }
-    // no conflicts
-    @Nullable
-    public String bar2(@Nullable String x) { return ""; }
-
-    // no conflicts
-    public String baz(String x) { return ""; }
-}
-
-// FILE: main.kt
-fun main(a: A, b: B, c: C) {
-    a.foo1(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>).length
-    a.foo2(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>).length
-    a.foo3(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>).length
-    a.bar1(null)<!UNSAFE_CALL!>.<!>length
-    a.bar2(null)<!UNSAFE_CALL!>.<!>length
-    a.baz(<!NULL_FOR_NONNULL_TYPE!>null<!>).length
-
-    <!RECEIVER_NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>b.foo1(null)<!>.length
-    b.foo1(null)?.length
-    b.foo2(<!NULL_FOR_NONNULL_TYPE!>null<!>).length
-    b.foo3(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>).length
-    b.bar1(null)<!UNSAFE_CALL!>.<!>length
-    b.bar2(null)<!UNSAFE_CALL!>.<!>length
-    <!RECEIVER_NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>b.baz(<!NULL_FOR_NONNULL_TYPE!>null<!>)<!>.length
-    b.baz(<!NULL_FOR_NONNULL_TYPE!>null<!>)?.length
-
-    c.foo1(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>).length
-    c.foo2(<!NULL_FOR_NONNULL_TYPE!>null<!>).length
-    c.foo3(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>).length
-    c.bar1(null)<!UNSAFE_CALL!>.<!>length
-    c.bar1(null)?.length
-    c.bar2(null)<!UNSAFE_CALL!>.<!>length
-    c.baz(<!NULL_FOR_NONNULL_TYPE!>null<!>).length
-}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.kt
index d7197d6eb90..a9012b10f60 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/tests/jsr305/nullabilityWarnings/typeQualifierDefault/nullabilityFromOverridden.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
 // JSR305_GLOBAL_REPORT: warn