diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt
index 70a811c31d7..860d2ae6d02 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt
@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.removeAnnotations
+import org.jetbrains.kotlin.ir.types.withHasQuestionMark
 import org.jetbrains.kotlin.ir.util.classId
 import org.jetbrains.kotlin.ir.util.coerceToUnitIfNeeded
 import org.jetbrains.kotlin.ir.util.parentAsClass
@@ -209,6 +210,9 @@ class Fir2IrImplicitCastInserter(
             expectedType.isUnit -> {
                 coerceToUnitIfNeeded(type, irBuiltIns)
             }
+            valueType.isNullabilityFlexible() && valueType.canBeNull && !expectedType.acceptsNullValues() -> {
+                insertImplicitNotNullCastIfNeeded(expression)
+            }
             valueType.hasEnhancedNullability() && !expectedType.acceptsNullValues() -> {
                 insertImplicitNotNullCastIfNeeded(expression)
             }
@@ -218,8 +222,16 @@ class Fir2IrImplicitCastInserter(
         }
     }
 
+    private fun FirTypeRef.isNullabilityFlexible(): Boolean {
+        if (hasFlexibleNullability()) {
+            return true
+        }
+        val flexibility = coneTypeSafe<ConeFlexibleType>() ?: return false
+        return flexibility.lowerBound.isMarkedNullable != flexibility.upperBound.isMarkedNullable
+    }
+
     private fun FirTypeRef.acceptsNullValues(): Boolean =
-        isMarkedNullable == true || hasEnhancedNullability()
+        canBeNull || hasEnhancedNullability()
 
     private fun IrExpression.insertImplicitNotNullCastIfNeeded(expression: FirExpression): IrExpression {
         // [TypeOperatorLowering] will retrieve the source (from start offset to end offset) as an assertion message.
@@ -227,9 +239,11 @@ class Fir2IrImplicitCastInserter(
         if (expression.source == null) {
             return this
         }
+        // Cast type massage 1. Remove @EnhancedNullability
+        // Cast type massage 2. Convert it to a non-null variant (in case of @FlexibleNullability)
         val castType = type.removeAnnotations {
             it.symbol.owner.parentAsClass.classId == CompilerConeAttributes.EnhancedNullability.ANNOTATION_CLASS_ID
-        }
+        }.withHasQuestionMark(false)
         return IrTypeOperatorCallImpl(
             this.startOffset,
             this.endOffset,
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt
index 28022b87cdd..5da22a8d3f5 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt
@@ -138,3 +138,20 @@ private fun ConeTypeParameterType.hasNotNullUpperBound(): Boolean {
         }
     }
 }
+
+val FirTypeRef.canBeNull: Boolean
+    get() = coneType.canBeNull
+
+val ConeKotlinType.canBeNull: Boolean
+    get() {
+        if (isMarkedNullable) {
+            return true
+        }
+        return when (this) {
+            is ConeFlexibleType -> upperBound.canBeNull
+            is ConeDefinitelyNotNullType -> false
+            is ConeTypeParameterType -> this.lookupTag.typeParameterSymbol.fir.bounds.any { it.canBeNull }
+            is ConeIntersectionType -> intersectedTypes.any { it.canBeNull }
+            else -> isNullable
+        }
+    }
\ No newline at end of file
diff --git a/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapGetOrDefault.kt b/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapGetOrDefault.kt
index 544a5e8212c..97c450bcb5f 100644
--- a/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapGetOrDefault.kt
+++ b/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapGetOrDefault.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // JVM_TARGET: 1.8
 // WITH_RUNTIME
diff --git a/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapRemove2.kt b/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapRemove2.kt
index e23d2ed3aec..5458fc23ea0 100644
--- a/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapRemove2.kt
+++ b/compiler/testData/codegen/box/casts/javaInterop/nullCheckOnMapRemove2.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // JVM_TARGET: 1.8
 // WITH_RUNTIME
diff --git a/compiler/testData/codegen/box/fullJdk/platformTypeAssertionStackTrace.kt b/compiler/testData/codegen/box/fullJdk/platformTypeAssertionStackTrace.kt
index 3c51754ba66..b5ba5b94fac 100644
--- a/compiler/testData/codegen/box/fullJdk/platformTypeAssertionStackTrace.kt
+++ b/compiler/testData/codegen/box/fullJdk/platformTypeAssertionStackTrace.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // FULL_JDK
diff --git a/compiler/testData/codegen/box/javaInterop/notNullAssertions/errorMessage.kt b/compiler/testData/codegen/box/javaInterop/notNullAssertions/errorMessage.kt
index f75c88a32e9..ce426fcf75d 100644
--- a/compiler/testData/codegen/box/javaInterop/notNullAssertions/errorMessage.kt
+++ b/compiler/testData/codegen/box/javaInterop/notNullAssertions/errorMessage.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // FILE: test.kt
 fun f(x: String) = "Fail 1"
diff --git a/compiler/testData/codegen/box/javaInterop/notNullAssertions/nullCheckOnLambdaReturnValue/stringVsTConstrained.kt b/compiler/testData/codegen/box/javaInterop/notNullAssertions/nullCheckOnLambdaReturnValue/stringVsTConstrained.kt
index f6e9bbf03be..6d2e7491f41 100644
--- a/compiler/testData/codegen/box/javaInterop/notNullAssertions/nullCheckOnLambdaReturnValue/stringVsTConstrained.kt
+++ b/compiler/testData/codegen/box/javaInterop/notNullAssertions/nullCheckOnLambdaReturnValue/stringVsTConstrained.kt
@@ -1,5 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND_FIR: JVM_IR
 // FILE: stringVsTConstrained.kt
 fun <T> useTConstrained(xs: Array<T>, fn: () -> T) = fn()
 
diff --git a/compiler/testData/codegen/box/javaInterop/notNullAssertions/staticCallErrorMessage.kt b/compiler/testData/codegen/box/javaInterop/notNullAssertions/staticCallErrorMessage.kt
index e45b126c20d..9255c5d583c 100644
--- a/compiler/testData/codegen/box/javaInterop/notNullAssertions/staticCallErrorMessage.kt
+++ b/compiler/testData/codegen/box/javaInterop/notNullAssertions/staticCallErrorMessage.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // FILE: test.kt
 fun f(x: String) = "Fail 1"
diff --git a/compiler/testData/codegen/bytecodeText/notNullAssertions/arrayListGet.kt b/compiler/testData/codegen/bytecodeText/notNullAssertions/arrayListGet.kt
index c6c2eae56f3..6c89da9e8a8 100644
--- a/compiler/testData/codegen/bytecodeText/notNullAssertions/arrayListGet.kt
+++ b/compiler/testData/codegen/bytecodeText/notNullAssertions/arrayListGet.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 import java.util.ArrayList
 
 fun foo(): Any {
diff --git a/compiler/testData/codegen/bytecodeText/notNullAssertions/assertionForNotNullCaptured.kt b/compiler/testData/codegen/bytecodeText/notNullAssertions/assertionForNotNullCaptured.kt
index de9551a47ab..3633b5db67b 100644
--- a/compiler/testData/codegen/bytecodeText/notNullAssertions/assertionForNotNullCaptured.kt
+++ b/compiler/testData/codegen/bytecodeText/notNullAssertions/assertionForNotNullCaptured.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 class A<T> {
     fun add(element: T) {}
 }
diff --git a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/deterministicNotNullChecks.kt b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/deterministicNotNullChecks.kt
index f180d292a36..9ba12a721a6 100644
--- a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/deterministicNotNullChecks.kt
+++ b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/deterministicNotNullChecks.kt
@@ -1,8 +1,4 @@
 // FILE: test/CallableDescriptor.java
-// IGNORE_BACKEND_FIR: JVM_IR
-// Here FIR adds implicit NOT_NULL cast for `origin`, resulting in an assertion being added,
-// which is the correct (yet mismatching) behavior, according to https://youtrack.jetbrains.com/issue/KT-35656
-
 // JVM_IR:
 // Here in 'original in emptySet<D>()' T = '@EnhancedNullability CallableDescriptor' is inferred for 'Iterable<T>.contains(T)'.
 // Using value of '@EnhancedNullability CallableDescriptor' type where '@EnhancedNullability CallableDescriptor' is expected
diff --git a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNull.kt b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNull.kt
index 8db917deb8a..758216e51e3 100644
--- a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNull.kt
+++ b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNull.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // FILE: j/J.java
 
 package j;
diff --git a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNullTwice.kt b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNullTwice.kt
index 01ac2aa4da5..ff2f16e7fda 100644
--- a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNullTwice.kt
+++ b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/expressionValueIsNotNullTwice.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // FILE: j/J.java
 
 package j;
diff --git a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/notNullExpressionValueTwice_1_4.kt b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/notNullExpressionValueTwice_1_4.kt
index a80f2c8a9e1..6cfa2e956a5 100644
--- a/compiler/testData/codegen/bytecodeText/nullCheckOptimization/notNullExpressionValueTwice_1_4.kt
+++ b/compiler/testData/codegen/bytecodeText/nullCheckOptimization/notNullExpressionValueTwice_1_4.kt
@@ -1,5 +1,4 @@
 // !API_VERSION: LATEST
-// IGNORE_BACKEND_FIR: JVM_IR
 // FILE: j/J.java
 
 package j;
diff --git a/compiler/testData/ir/irText/expressions/implicitCastOnPlatformType.fir.txt b/compiler/testData/ir/irText/expressions/implicitCastOnPlatformType.fir.txt
index f7841f19a32..48a7778edda 100644
--- a/compiler/testData/ir/irText/expressions/implicitCastOnPlatformType.fir.txt
+++ b/compiler/testData/ir/irText/expressions/implicitCastOnPlatformType.fir.txt
@@ -2,5 +2,6 @@ FILE fqName:<root> fileName:/implicitCastOnPlatformType.kt
   FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun test (): kotlin.String declared in <root>'
-        CALL 'public open fun getProperty (p0: kotlin.String?): kotlin.String? declared in java.lang.System' type=kotlin.String? origin=null
-          p0: CONST String type=kotlin.String value="test"
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          CALL 'public open fun getProperty (p0: kotlin.String?): kotlin.String? declared in java.lang.System' type=kotlin.String? origin=null
+            p0: CONST String type=kotlin.String value="test"
diff --git a/compiler/testData/ir/irText/expressions/nullCheckOnLambdaReturn.fir.txt b/compiler/testData/ir/irText/expressions/nullCheckOnLambdaReturn.fir.txt
index 5119c9fe99e..e51da36277b 100644
--- a/compiler/testData/ir/irText/expressions/nullCheckOnLambdaReturn.fir.txt
+++ b/compiler/testData/ir/irText/expressions/nullCheckOnLambdaReturn.fir.txt
@@ -25,7 +25,8 @@ FILE fqName:<root> fileName:/nullCheckOnLambdaReturn.kt
             FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.Any
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Any declared in <root>.test1'
-                  CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+                  TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+                    CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
   PROPERTY name:test2 visibility:public modality:FINAL [val]
     FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
       EXPRESSION_BODY
diff --git a/compiler/testData/ir/irText/expressions/sam/genericSamSmartcast.fir.txt b/compiler/testData/ir/irText/expressions/sam/genericSamSmartcast.fir.txt
index d25cef9cccb..7eefb793044 100644
--- a/compiler/testData/ir/irText/expressions/sam/genericSamSmartcast.fir.txt
+++ b/compiler/testData/ir/irText/expressions/sam/genericSamSmartcast.fir.txt
@@ -7,15 +7,16 @@ FILE fqName:<root> fileName:/genericSamSmartcast.kt
           if: TYPE_OP type=kotlin.Boolean origin=INSTANCEOF typeOperand=<root>.A<*>
             GET_VAR 'x: kotlin.Any declared in <root>.f' type=kotlin.Any origin=null
           then: RETURN type=kotlin.Nothing from='public final fun f (x: kotlin.Any): kotlin.String declared in <root>'
-            CALL 'public open fun call (block: <root>.A.I<T of <root>.A?>?): kotlin.String? declared in <root>.A' type=kotlin.String? origin=null
-              $this: TYPE_OP type=<root>.A<*> origin=IMPLICIT_CAST typeOperand=<root>.A<*>
-                GET_VAR 'x: kotlin.Any declared in <root>.f' type=kotlin.Any origin=null
-              block: TYPE_OP type=<root>.A.I<kotlin.Any?>? origin=SAM_CONVERSION typeOperand=<root>.A.I<kotlin.Any?>?
-                FUN_EXPR type=kotlin.Function1<kotlin.Any?, kotlin.String?> origin=LAMBDA
-                  FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> (y:kotlin.Any?) returnType:kotlin.String?
-                    VALUE_PARAMETER name:y index:0 type:kotlin.Any?
-                    BLOCK_BODY
-                      RETURN type=kotlin.Nothing from='local final fun <anonymous> (y: kotlin.Any?): kotlin.String? declared in <root>.f'
-                        CONST String type=kotlin.String value="OK"
+            TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+              CALL 'public open fun call (block: <root>.A.I<T of <root>.A?>?): kotlin.String? declared in <root>.A' type=kotlin.String? origin=null
+                $this: TYPE_OP type=<root>.A<*> origin=IMPLICIT_CAST typeOperand=<root>.A<*>
+                  GET_VAR 'x: kotlin.Any declared in <root>.f' type=kotlin.Any origin=null
+                block: TYPE_OP type=<root>.A.I<kotlin.Any?>? origin=SAM_CONVERSION typeOperand=<root>.A.I<kotlin.Any?>?
+                  FUN_EXPR type=kotlin.Function1<kotlin.Any?, kotlin.String?> origin=LAMBDA
+                    FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> (y:kotlin.Any?) returnType:kotlin.String?
+                      VALUE_PARAMETER name:y index:0 type:kotlin.Any?
+                      BLOCK_BODY
+                        RETURN type=kotlin.Nothing from='local final fun <anonymous> (y: kotlin.Any?): kotlin.String? declared in <root>.f'
+                          CONST String type=kotlin.String value="OK"
       RETURN type=kotlin.Nothing from='public final fun f (x: kotlin.Any): kotlin.String declared in <root>'
         CONST String type=kotlin.String value="Fail"
diff --git a/compiler/testData/ir/irText/expressions/sam/samConstructors.fir.txt b/compiler/testData/ir/irText/expressions/sam/samConstructors.fir.txt
index 76d3d8cba80..bb21c34f27d 100644
--- a/compiler/testData/ir/irText/expressions/sam/samConstructors.fir.txt
+++ b/compiler/testData/ir/irText/expressions/sam/samConstructors.fir.txt
@@ -33,4 +33,5 @@ FILE fqName:<root> fileName:/samConstructors.kt
                 RETURN type=kotlin.Nothing from='local final fun <anonymous> (a: kotlin.Int?, b: kotlin.Int?): kotlin.Int declared in <root>.test4'
                   CALL 'public final fun minus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=MINUS
                     $this: GET_VAR 'a: kotlin.Int? declared in <root>.test4.<anonymous>' type=kotlin.Int? origin=null
-                    other: GET_VAR 'b: kotlin.Int? declared in <root>.test4.<anonymous>' type=kotlin.Int? origin=null
+                    other: TYPE_OP type=kotlin.Int origin=IMPLICIT_NOTNULL typeOperand=kotlin.Int
+                      GET_VAR 'b: kotlin.Int? declared in <root>.test4.<anonymous>' type=kotlin.Int? origin=null
diff --git a/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInDestructuringAssignment.fir.txt b/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInDestructuringAssignment.fir.txt
index 7ac01e935d9..2fb5458168d 100644
--- a/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInDestructuringAssignment.fir.txt
+++ b/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInDestructuringAssignment.fir.txt
@@ -141,7 +141,8 @@ FILE fqName:<root> fileName:/enhancedNullabilityInDestructuringAssignment.kt
           $this: GET_VAR 'val tmp_1: <root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?>? [val] declared in <root>.test2' type=<root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?>? origin=null
       CALL 'public final fun use (x: kotlin.Any, y: kotlin.Any): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         x: GET_VAR 'val x: @[FlexibleNullability] kotlin.String [val] declared in <root>.test2' type=@[FlexibleNullability] kotlin.String origin=null
-        y: GET_VAR 'val y: kotlin.String? [val] declared in <root>.test2' type=kotlin.String? origin=null
+        y: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          GET_VAR 'val y: kotlin.String? [val] declared in <root>.test2' type=kotlin.String? origin=null
   FUN name:test2Desugared visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       VAR name:tmp type:<root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?>? [val]
@@ -154,7 +155,8 @@ FILE fqName:<root> fileName:/enhancedNullabilityInDestructuringAssignment.kt
           $this: GET_VAR 'val tmp: <root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?>? [val] declared in <root>.test2Desugared' type=<root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?>? origin=null
       CALL 'public final fun use (x: kotlin.Any, y: kotlin.Any): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         x: GET_VAR 'val x: @[FlexibleNullability] kotlin.String [val] declared in <root>.test2Desugared' type=@[FlexibleNullability] kotlin.String origin=null
-        y: GET_VAR 'val y: kotlin.String? [val] declared in <root>.test2Desugared' type=kotlin.String? origin=null
+        y: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          GET_VAR 'val y: kotlin.String? [val] declared in <root>.test2Desugared' type=kotlin.String? origin=null
   FUN name:test3 visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       VAR IR_TEMPORARY_VARIABLE name:tmp_2 type:<root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?> [val]
@@ -168,7 +170,8 @@ FILE fqName:<root> fileName:/enhancedNullabilityInDestructuringAssignment.kt
           $this: GET_VAR 'val tmp_2: <root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?> [val] declared in <root>.test3' type=<root>.Q<@[FlexibleNullability] kotlin.String, kotlin.String?> origin=null
       CALL 'public final fun use (x: kotlin.Any, y: kotlin.Any): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         x: GET_VAR 'val x: @[FlexibleNullability] kotlin.String [val] declared in <root>.test3' type=@[FlexibleNullability] kotlin.String origin=null
-        y: GET_VAR 'val y: kotlin.String? [val] declared in <root>.test3' type=kotlin.String? origin=null
+        y: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          GET_VAR 'val y: kotlin.String? [val] declared in <root>.test3' type=kotlin.String? origin=null
   FUN name:test4 visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       VAR IR_TEMPORARY_VARIABLE name:tmp_3 type:kotlin.collections.IndexedValue<<root>.P?> [val]
@@ -185,4 +188,5 @@ FILE fqName:<root> fileName:/enhancedNullabilityInDestructuringAssignment.kt
           $this: GET_VAR 'val tmp_3: kotlin.collections.IndexedValue<<root>.P?> [val] declared in <root>.test4' type=kotlin.collections.IndexedValue<<root>.P?> origin=null
       CALL 'public final fun use (x: kotlin.Any, y: kotlin.Any): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         x: GET_VAR 'val x: kotlin.Int [val] declared in <root>.test4' type=kotlin.Int origin=null
-        y: GET_VAR 'val y: <root>.P? [val] declared in <root>.test4' type=<root>.P? origin=null
+        y: TYPE_OP type=<root>.P origin=IMPLICIT_NOTNULL typeOperand=<root>.P
+          GET_VAR 'val y: <root>.P? [val] declared in <root>.test4' type=<root>.P? origin=null
diff --git a/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInForLoop.fir.txt b/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInForLoop.fir.txt
index 50826e6b84d..9cf32cd3d9e 100644
--- a/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInForLoop.fir.txt
+++ b/compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInForLoop.fir.txt
@@ -75,7 +75,8 @@ FILE fqName:<root> fileName:/enhancedNullabilityInForLoop.kt
               CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [fake_override,operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'val tmp_3: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListUse' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
             CALL 'public final fun use (s: <root>.P): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-              s: GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInListUse' type=<root>.P? origin=null
+              s: TYPE_OP type=<root>.P origin=IMPLICIT_NOTNULL typeOperand=<root>.P
+                GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInListUse' type=<root>.P? origin=null
             CALL 'public open fun use (s: @[EnhancedNullability] <root>.P): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
               s: GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInListUse' type=<root>.P? origin=null
   FUN name:testForInArrayUse visibility:public modality:FINAL <> (j:<root>.J) returnType:kotlin.Unit
@@ -94,7 +95,8 @@ FILE fqName:<root> fileName:/enhancedNullabilityInForLoop.kt
               CALL 'public abstract fun next (): T of kotlin.collections.Iterator [operator] declared in kotlin.collections.Iterator' type=<root>.P? origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'val tmp_4: kotlin.collections.Iterator<<root>.P?> [val] declared in <root>.testForInArrayUse' type=kotlin.collections.Iterator<<root>.P?> origin=null
             CALL 'public final fun use (s: <root>.P): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-              s: GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInArrayUse' type=<root>.P? origin=null
+              s: TYPE_OP type=<root>.P origin=IMPLICIT_NOTNULL typeOperand=<root>.P
+                GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInArrayUse' type=<root>.P? origin=null
             CALL 'public open fun use (s: @[EnhancedNullability] <root>.P): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
               s: GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInArrayUse' type=<root>.P? origin=null
   CLASS INTERFACE name:K modality:ABSTRACT visibility:public superTypes:[kotlin.Any]
diff --git a/compiler/testData/ir/irText/types/nullChecks/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.fir.txt b/compiler/testData/ir/irText/types/nullChecks/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.fir.txt
index 2e3c14c17b6..63b46434e8f 100644
--- a/compiler/testData/ir/irText/types/nullChecks/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.fir.txt
+++ b/compiler/testData/ir/irText/types/nullChecks/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.fir.txt
@@ -31,8 +31,9 @@ FILE fqName:<root> fileName:/explicitEqualsAndCompareToCallsOnPlatformTypeReceiv
         CALL 'public open fun compareTo (other: kotlin.Double): kotlin.Int [operator] declared in kotlin.Double' type=kotlin.Int origin=null
           $this: CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
             $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformCompareToPlatform' type=<root>.JavaClass origin=null
-          other: CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
-            $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformCompareToPlatform' type=<root>.JavaClass origin=null
+          other: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformCompareToPlatform' type=<root>.JavaClass origin=null
   FUN name:testPlatformCompareToKotlin visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Int
     $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
     BLOCK_BODY
@@ -47,5 +48,6 @@ FILE fqName:<root> fileName:/explicitEqualsAndCompareToCallsOnPlatformTypeReceiv
       RETURN type=kotlin.Nothing from='public final fun testKotlinCompareToPlatform (): kotlin.Int declared in <root>'
         CALL 'public open fun compareTo (other: kotlin.Double): kotlin.Int [operator] declared in kotlin.Double' type=kotlin.Int origin=null
           $this: CONST Double type=kotlin.Double value=0.0
-          other: CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
-            $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testKotlinCompareToPlatform' type=<root>.JavaClass origin=null
+          other: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testKotlinCompareToPlatform' type=<root>.JavaClass origin=null
diff --git a/compiler/testData/ir/irText/types/nullChecks/implicitNotNullOnPlatformType.fir.txt b/compiler/testData/ir/irText/types/nullChecks/implicitNotNullOnPlatformType.fir.txt
index 887af12416c..48b734647ea 100644
--- a/compiler/testData/ir/irText/types/nullChecks/implicitNotNullOnPlatformType.fir.txt
+++ b/compiler/testData/ir/irText/types/nullChecks/implicitNotNullOnPlatformType.fir.txt
@@ -63,16 +63,19 @@ FILE fqName:<root> fileName:/implicitNotNullOnPlatformType.kt
   FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun f (s: kotlin.String): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        s: CALL 'public open fun s (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+        s: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          CALL 'public open fun s (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
       CALL 'public final fun f (s: kotlin.String): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        s: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:STRING type:kotlin.String? visibility:public [static]' type=kotlin.String? origin=GET_PROPERTY
+        s: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:STRING type:kotlin.String? visibility:public [static]' type=kotlin.String? origin=GET_PROPERTY
   FUN name:testContains visibility:public modality:FINAL <> (m:<root>.MySet) returnType:kotlin.Unit
     VALUE_PARAMETER name:m index:0 type:<root>.MySet
     BLOCK_BODY
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL 'public final fun contains (element: kotlin.String): kotlin.Boolean [operator] declared in <root>.MySet' type=kotlin.Boolean origin=null
           $this: GET_VAR 'm: <root>.MySet declared in <root>.testContains' type=<root>.MySet origin=null
-          element: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:STRING type:kotlin.String? visibility:public [static]' type=kotlin.String? origin=GET_PROPERTY
+          element: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+            GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:STRING type:kotlin.String? visibility:public [static]' type=kotlin.String? origin=GET_PROPERTY
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL 'public final fun contains (element: kotlin.String): kotlin.Boolean [operator] declared in <root>.MySet' type=kotlin.Boolean origin=null
           $this: GET_VAR 'm: <root>.MySet declared in <root>.testContains' type=<root>.MySet origin=null
diff --git a/compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/stringVsTConstrained.fir.txt b/compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/stringVsTConstrained.fir.txt
index 9072f71313c..d06da6b5448 100644
--- a/compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/stringVsTConstrained.fir.txt
+++ b/compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/stringVsTConstrained.fir.txt
@@ -18,4 +18,5 @@ FILE fqName:<root> fileName:/stringVsTConstrained.kt
             FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String declared in <root>.testWithNullCheck'
-                  CALL 'public open fun string (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+                  TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+                    CALL 'public open fun string (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
diff --git a/compiler/testData/ir/irText/types/smartCastOnFieldReceiverOfGenericType.fir.txt b/compiler/testData/ir/irText/types/smartCastOnFieldReceiverOfGenericType.fir.txt
index 39d947804da..8c9701788ee 100644
--- a/compiler/testData/ir/irText/types/smartCastOnFieldReceiverOfGenericType.fir.txt
+++ b/compiler/testData/ir/irText/types/smartCastOnFieldReceiverOfGenericType.fir.txt
@@ -21,6 +21,7 @@ FILE fqName:<root> fileName:/smartCastOnFieldReceiverOfGenericType.kt
         TYPE_OP type=<root>.JCell<kotlin.String> origin=CAST typeOperand=<root>.JCell<kotlin.String>
           GET_VAR 'a: kotlin.Any declared in <root>.testGetField' type=kotlin.Any origin=null
       RETURN type=kotlin.Nothing from='public final fun testGetField (a: kotlin.Any): kotlin.String declared in <root>'
-        GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:value type:T of <root>.JCell? visibility:public' type=kotlin.String? origin=GET_PROPERTY
-          receiver: TYPE_OP type=<root>.JCell<kotlin.String> origin=IMPLICIT_CAST typeOperand=<root>.JCell<kotlin.String>
-            GET_VAR 'a: kotlin.Any declared in <root>.testGetField' type=kotlin.Any origin=null
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:value type:T of <root>.JCell? visibility:public' type=kotlin.String? origin=GET_PROPERTY
+            receiver: TYPE_OP type=<root>.JCell<kotlin.String> origin=IMPLICIT_CAST typeOperand=<root>.JCell<kotlin.String>
+              GET_VAR 'a: kotlin.Any declared in <root>.testGetField' type=kotlin.Any origin=null