diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirBodyResolveTransformer.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirBodyResolveTransformer.kt
index bd213c36683..c9fe351c1b0 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirBodyResolveTransformer.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirBodyResolveTransformer.kt
@@ -526,7 +526,7 @@ open class FirBodyResolveTransformer(
             whenExpression.transformSubject(this, noExpectedType)
             if (whenExpression.isOneBranch()) {
                 whenExpression.transformBranches(this, noExpectedType)
-                whenExpression.resultType = builtinTypes.unitType
+                whenExpression.resultType = whenExpression.branches.first().result.resultType
                 dataFlowAnalyzer.exitWhenExpression(whenExpression)
                 return@with whenExpression.compose()
             }
diff --git a/compiler/fir/resolve/testData/resolve/arguments/lambda.txt b/compiler/fir/resolve/testData/resolve/arguments/lambda.txt
index 05024d95752..d94db3b7dbe 100644
--- a/compiler/fir/resolve/testData/resolve/arguments/lambda.txt
+++ b/compiler/fir/resolve/testData/resolve/arguments/lambda.txt
@@ -22,7 +22,7 @@ FILE: lambda.kt
             Unit
         }
         )
-        <Inapplicable(PARAMETER_MAPPING_ERROR): [/foo]>#(f = foo@fun <implicit>.<anonymous>(): <implicit> {
+        <Inapplicable(PARAMETER_MAPPING_ERROR): [/foo]>#(f = foo@fun <implicit>.<anonymous>(): <implicit> <kind=EXACTLY_ONCE>  {
             Unit
         }
         , <L> = foo@fun <implicit>.<anonymous>(): <implicit> <kind=EXACTLY_ONCE>  {
@@ -41,7 +41,7 @@ FILE: lambda.kt
             Unit
         }
         )
-        R|/bar|(x = Int(1), f = bar@fun <anonymous>(): R|kotlin/Unit| {
+        R|/bar|(x = Int(1), f = bar@fun <anonymous>(): R|kotlin/Unit| <kind=EXACTLY_ONCE>  {
             Unit
         }
         )
@@ -53,7 +53,7 @@ FILE: lambda.kt
             Unit
         }
         )
-        R|/baz|(other = Boolean(false), f = baz@fun <anonymous>(): R|kotlin/Unit| {
+        R|/baz|(other = Boolean(false), f = baz@fun <anonymous>(): R|kotlin/Unit| <kind=EXACTLY_ONCE>  {
             Unit
         }
         )
diff --git a/compiler/testData/ir/irText/expressions/bangbang.fir.txt b/compiler/testData/ir/irText/expressions/bangbang.fir.txt
index 0ba9f82bc71..54934b51c6f 100644
--- a/compiler/testData/ir/irText/expressions/bangbang.fir.txt
+++ b/compiler/testData/ir/irText/expressions/bangbang.fir.txt
@@ -59,7 +59,7 @@ FILE fqName:<root> fileName:/bangbang.kt
     TYPE_PARAMETER name:X index:0 variance: superTypes:[]
     VALUE_PARAMETER name:a index:0 type:X of <root>.test4
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=INSTANCEOF typeOperand=kotlin.String?
             GET_VAR 'a: X of <root>.test4 declared in <root>.test4' type=X of <root>.test4 origin=null
diff --git a/compiler/testData/ir/irText/expressions/breakContinueInLoopHeader.fir.txt b/compiler/testData/ir/irText/expressions/breakContinueInLoopHeader.fir.txt
index 8f60da1416a..3f6c055a01d 100644
--- a/compiler/testData/ir/irText/expressions/breakContinueInLoopHeader.fir.txt
+++ b/compiler/testData/ir/irText/expressions/breakContinueInLoopHeader.fir.txt
@@ -103,7 +103,7 @@ FILE fqName:<root> fileName:/breakContinueInLoopHeader.kt
         CONST Int type=kotlin.Int value=0
       WHILE label=Outer origin=WHILE_LOOP
         condition: CONST Boolean type=kotlin.Boolean value=true
-        body: BLOCK type=kotlin.Unit origin=null
+        body: BLOCK type=kotlin.Nothing origin=null
           VAR name:<unary> type:kotlin.Int [val]
             GET_VAR 'var i: kotlin.Int [var] declared in <root>.test5' type=kotlin.Int origin=null
           SET_VAR 'var i: kotlin.Int [var] declared in <root>.test5' type=kotlin.Int origin=null
@@ -129,7 +129,7 @@ FILE fqName:<root> fileName:/breakContinueInLoopHeader.kt
               BRANCH
                 if: CONST Boolean type=kotlin.Boolean value=true
                 then: BREAK label=null loop.label=Outer
-          WHEN type=kotlin.Unit origin=IF
+          WHEN type=kotlin.Nothing origin=IF
             BRANCH
               if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
                 arg0: GET_VAR 'var i: kotlin.Int [var] declared in <root>.test5' type=kotlin.Int origin=null
diff --git a/compiler/testData/ir/irText/expressions/breakContinueInWhen.fir.txt b/compiler/testData/ir/irText/expressions/breakContinueInWhen.fir.txt
index 6f9d9a0c93f..db13e2f6682 100644
--- a/compiler/testData/ir/irText/expressions/breakContinueInWhen.fir.txt
+++ b/compiler/testData/ir/irText/expressions/breakContinueInWhen.fir.txt
@@ -19,11 +19,11 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
       WHILE label=null origin=FOR_LOOP_INNER_WHILE
         condition: CALL 'public abstract fun hasNext (): kotlin.Boolean declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=null
           $this: GET_VAR 'val <iterator>: kotlin.collections.IntIterator [val] declared in <root>.testBreakFor' type=kotlin.collections.IntIterator origin=null
-        body: BLOCK type=kotlin.Unit origin=null
+        body: BLOCK type=kotlin.Nothing origin=null
           VAR name:x type:kotlin.Int [val]
             CALL 'public final fun next (): kotlin.Int declared in kotlin.collections.IntIterator' type=kotlin.Int origin=null
               $this: GET_VAR 'val <iterator>: kotlin.collections.IntIterator [val] declared in <root>.testBreakFor' type=kotlin.collections.IntIterator origin=null
-          WHEN type=kotlin.Unit origin=WHEN
+          WHEN type=kotlin.Nothing origin=WHEN
             BRANCH
               if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
                 arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testBreakFor' type=kotlin.Int origin=null
@@ -37,7 +37,7 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
         condition: CALL 'public final fun less (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=LT
           arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testBreakWhile' type=kotlin.Int origin=null
           arg1: CONST Int type=kotlin.Int value=10
-        body: WHEN type=kotlin.Unit origin=WHEN
+        body: WHEN type=kotlin.Nothing origin=WHEN
           BRANCH
             if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
               arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testBreakWhile' type=kotlin.Int origin=null
@@ -48,7 +48,7 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
       VAR name:k type:kotlin.Int [var]
         CONST Int type=kotlin.Int value=0
       DO_WHILE label=null origin=DO_WHILE_LOOP
-        body: WHEN type=kotlin.Unit origin=WHEN
+        body: WHEN type=kotlin.Nothing origin=WHEN
           BRANCH
             if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
               arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testBreakDoWhile' type=kotlin.Int origin=null
@@ -77,11 +77,11 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
       WHILE label=null origin=FOR_LOOP_INNER_WHILE
         condition: CALL 'public abstract fun hasNext (): kotlin.Boolean declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=null
           $this: GET_VAR 'val <iterator>: kotlin.collections.IntIterator [val] declared in <root>.testContinueFor' type=kotlin.collections.IntIterator origin=null
-        body: BLOCK type=kotlin.Unit origin=null
+        body: BLOCK type=kotlin.Nothing origin=null
           VAR name:x type:kotlin.Int [val]
             CALL 'public final fun next (): kotlin.Int declared in kotlin.collections.IntIterator' type=kotlin.Int origin=null
               $this: GET_VAR 'val <iterator>: kotlin.collections.IntIterator [val] declared in <root>.testContinueFor' type=kotlin.collections.IntIterator origin=null
-          WHEN type=kotlin.Unit origin=WHEN
+          WHEN type=kotlin.Nothing origin=WHEN
             BRANCH
               if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
                 arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testContinueFor' type=kotlin.Int origin=null
@@ -95,7 +95,7 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
         condition: CALL 'public final fun less (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=LT
           arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testContinueWhile' type=kotlin.Int origin=null
           arg1: CONST Int type=kotlin.Int value=10
-        body: WHEN type=kotlin.Unit origin=WHEN
+        body: WHEN type=kotlin.Nothing origin=WHEN
           BRANCH
             if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
               arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testContinueWhile' type=kotlin.Int origin=null
@@ -115,7 +115,7 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
             CALL 'public final fun inc (): kotlin.Int declared in kotlin.Int' type=kotlin.Int origin=null
               $this: GET_VAR 'val <unary>: kotlin.Int [val] declared in <root>.testContinueDoWhile' type=kotlin.Int origin=null
           GET_VAR 'var k: kotlin.Int [var] declared in <root>.testContinueDoWhile' type=kotlin.Int origin=null
-          WHEN type=kotlin.Unit origin=WHEN
+          WHEN type=kotlin.Nothing origin=WHEN
             BRANCH
               if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
                 arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testContinueDoWhile' type=kotlin.Int origin=null
@@ -128,7 +128,7 @@ FILE fqName:<root> fileName:/breakContinueInWhen.kt
         condition: CALL 'public final fun less (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=LT
           arg0: GET_VAR 'var k: kotlin.Int [var] declared in <root>.testContinueDoWhile' type=kotlin.Int origin=null
           arg1: CONST Int type=kotlin.Int value=10
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Nothing origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
diff --git a/compiler/testData/ir/irText/expressions/castToTypeParameter.fir.txt b/compiler/testData/ir/irText/expressions/castToTypeParameter.fir.txt
index ddd987d97ee..a112679f726 100644
--- a/compiler/testData/ir/irText/expressions/castToTypeParameter.fir.txt
+++ b/compiler/testData/ir/irText/expressions/castToTypeParameter.fir.txt
@@ -72,7 +72,7 @@ FILE fqName:<root> fileName:/castToTypeParameter.kt
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public final fun <get-castGenericMemberExtVal> (): TV of <uninitialized parent> declared in <root>.Host'
             TYPE_OP type=TV of <uninitialized parent> origin=CAST typeOperand=TV of <uninitialized parent>
-              GET_VAR '<this>: <root>.Host declared in <root>.Host' type=<root>.Host<T of <root>.Host> origin=null
+              GET_VAR '<this>: <root>.Host declared in <root>.Host' type=T of <root>.Host origin=null
     FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
diff --git a/compiler/testData/ir/irText/expressions/elvis.fir.txt b/compiler/testData/ir/irText/expressions/elvis.fir.txt
index e916d3367da..6c9020c2024 100644
--- a/compiler/testData/ir/irText/expressions/elvis.fir.txt
+++ b/compiler/testData/ir/irText/expressions/elvis.fir.txt
@@ -50,13 +50,13 @@ FILE fqName:<root> fileName:/elvis.kt
     VALUE_PARAMETER name:a index:0 type:kotlin.Any?
     VALUE_PARAMETER name:b index:1 type:kotlin.Any?
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.String
             GET_VAR 'b: kotlin.Any? declared in <root>.test3' type=kotlin.Any? origin=null
           then: RETURN type=kotlin.Nothing from='public final fun test3 (a: kotlin.Any?, b: kotlin.Any?): kotlin.String declared in <root>'
             CONST String type=kotlin.String value=""
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.String?
             GET_VAR 'a: kotlin.Any? declared in <root>.test3' type=kotlin.Any? origin=null
diff --git a/compiler/testData/ir/irText/expressions/floatingPointComparisons/whenByFloatingPoint.fir.txt b/compiler/testData/ir/irText/expressions/floatingPointComparisons/whenByFloatingPoint.fir.txt
index 1b8f933ec20..d3b032450c9 100644
--- a/compiler/testData/ir/irText/expressions/floatingPointComparisons/whenByFloatingPoint.fir.txt
+++ b/compiler/testData/ir/irText/expressions/floatingPointComparisons/whenByFloatingPoint.fir.txt
@@ -17,7 +17,7 @@ FILE fqName:<root> fileName:/whenByFloatingPoint.kt
   FUN name:testSmartCastInWhenSubject visibility:public modality:FINAL <> (x:kotlin.Any) returnType:kotlin.Int
     VALUE_PARAMETER name:x index:0 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Int origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.Double
             GET_VAR 'x: kotlin.Any declared in <root>.testSmartCastInWhenSubject' type=kotlin.Any origin=null
@@ -40,7 +40,7 @@ FILE fqName:<root> fileName:/whenByFloatingPoint.kt
     VALUE_PARAMETER name:x index:0 type:kotlin.Double
     VALUE_PARAMETER name:y index:1 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Int origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.Double
             GET_VAR 'y: kotlin.Any declared in <root>.testSmartCastInWhenCondition' type=kotlin.Any origin=null
@@ -83,14 +83,14 @@ FILE fqName:<root> fileName:/whenByFloatingPoint.kt
     VALUE_PARAMETER name:x index:0 type:kotlin.Any
     VALUE_PARAMETER name:y index:1 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Int origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.Double
             GET_VAR 'x: kotlin.Any declared in <root>.testSmartCastToDifferentTypes' type=kotlin.Any origin=null
           then: RETURN type=kotlin.Nothing from='public final fun testSmartCastToDifferentTypes (x: kotlin.Any, y: kotlin.Any): kotlin.Int declared in <root>'
             CALL 'public final fun unaryMinus (): kotlin.Int declared in kotlin.Int' type=kotlin.Int origin=null
               $this: CONST Int type=kotlin.Int value=1
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Int origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.Float
             GET_VAR 'y: kotlin.Any declared in <root>.testSmartCastToDifferentTypes' type=kotlin.Any origin=null
diff --git a/compiler/testData/ir/irText/expressions/genericPropertyRef.fir.txt b/compiler/testData/ir/irText/expressions/genericPropertyRef.fir.txt
index 5cd8547ed63..3de18c915d3 100644
--- a/compiler/testData/ir/irText/expressions/genericPropertyRef.fir.txt
+++ b/compiler/testData/ir/irText/expressions/genericPropertyRef.fir.txt
@@ -131,7 +131,7 @@ FILE fqName:<root> fileName:/genericPropertyRef.kt
   PROPERTY name:recivier visibility:public modality:FINAL [var]
     FIELD PROPERTY_BACKING_FIELD name:recivier type:kotlin.Any? visibility:private [static]
       EXPRESSION_BODY
-        CONST String type=kotlin.Any? value="fail"
+        CONST String type=kotlin.Any value="fail"
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-recivier> visibility:public modality:FINAL <> () returnType:kotlin.Any?
       correspondingProperty: PROPERTY name:recivier visibility:public modality:FINAL [var]
       BLOCK_BODY
@@ -146,7 +146,7 @@ FILE fqName:<root> fileName:/genericPropertyRef.kt
   PROPERTY name:value2 visibility:public modality:FINAL [var]
     FIELD PROPERTY_BACKING_FIELD name:value2 type:kotlin.Any? visibility:private [static]
       EXPRESSION_BODY
-        CONST String type=kotlin.Any? value="fail2"
+        CONST String type=kotlin.Any value="fail2"
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-value2> visibility:public modality:FINAL <> () returnType:kotlin.Any?
       correspondingProperty: PROPERTY name:value2 visibility:public modality:FINAL [var]
       BLOCK_BODY
@@ -181,4 +181,3 @@ FILE fqName:<root> fileName:/genericPropertyRef.kt
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public final fun <get-barRef> (): kotlin.String.Companion declared in <root>'
           GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:barRef type:kotlin.String.Companion visibility:private [final,static]' type=kotlin.String.Companion origin=null
-
diff --git a/compiler/testData/ir/irText/expressions/ifElseIf.fir.txt b/compiler/testData/ir/irText/expressions/ifElseIf.fir.txt
index 6556643aa7d..8b60164ef6a 100644
--- a/compiler/testData/ir/irText/expressions/ifElseIf.fir.txt
+++ b/compiler/testData/ir/irText/expressions/ifElseIf.fir.txt
@@ -31,7 +31,7 @@ FILE fqName:<root> fileName:/ifElseIf.kt
         BRANCH
           if: CONST Boolean type=kotlin.Boolean value=true
           then: CONST Boolean type=kotlin.Boolean value=true
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Boolean origin=IF
         BRANCH
           if: GET_VAR 'flag: kotlin.Boolean declared in <root>.testEmptyBranches1' type=kotlin.Boolean origin=null
           then: CONST Boolean type=kotlin.Boolean value=true
diff --git a/compiler/testData/ir/irText/expressions/implicitCastToTypeParameter.fir.txt b/compiler/testData/ir/irText/expressions/implicitCastToTypeParameter.fir.txt
index ade8f6d8b70..c2d0273e558 100644
--- a/compiler/testData/ir/irText/expressions/implicitCastToTypeParameter.fir.txt
+++ b/compiler/testData/ir/irText/expressions/implicitCastToTypeParameter.fir.txt
@@ -4,11 +4,11 @@ FILE fqName:<root> fileName:/implicitCastToTypeParameter.kt
     $receiver: VALUE_PARAMETER name:<this> type:kotlin.Any
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun test1 <T> (): T of <root>.test1? [inline] declared in <root>'
-        WHEN type=kotlin.Any? origin=IF
+        WHEN type=T of <root>.test1? origin=IF
           BRANCH
             if: TYPE_OP type=kotlin.Boolean origin=INSTANCEOF typeOperand=T of <root>.test1
               GET_VAR '<this>: kotlin.Any declared in <root>.test1' type=kotlin.Any origin=null
-            then: GET_VAR '<this>: kotlin.Any declared in <root>.test1' type=kotlin.Any origin=null
+            then: GET_VAR '<this>: kotlin.Any declared in <root>.test1' type=T of <root>.test1 origin=null
           BRANCH
             if: CONST Boolean type=kotlin.Boolean value=true
             then: CONST Null type=kotlin.Nothing? value=null
diff --git a/compiler/testData/ir/irText/expressions/kt24804.fir.txt b/compiler/testData/ir/irText/expressions/kt24804.fir.txt
index 27b548313f4..d6e4e53dc37 100644
--- a/compiler/testData/ir/irText/expressions/kt24804.fir.txt
+++ b/compiler/testData/ir/irText/expressions/kt24804.fir.txt
@@ -10,21 +10,21 @@ FILE fqName:<root> fileName:/kt24804.kt
       VAR name:z type:kotlin.Int [var]
         CONST Int type=kotlin.Int value=10
       DO_WHILE label=l2 origin=DO_WHILE_LOOP
-        body: BLOCK type=kotlin.Unit origin=null
+        body: BLOCK type=kotlin.Nothing origin=null
           SET_VAR 'var z: kotlin.Int [var] declared in <root>.run' type=kotlin.Int origin=null
             CONST Int type=kotlin.Int value=1
-          WHEN type=kotlin.Unit origin=IF
+          WHEN type=kotlin.String origin=IF
             BRANCH
               if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
                 arg0: GET_VAR 'var z: kotlin.Int [var] declared in <root>.run' type=kotlin.Int origin=null
                 arg1: CONST Int type=kotlin.Int value=100
               then: RETURN type=kotlin.Nothing from='public final fun run (x: kotlin.Boolean, y: kotlin.Boolean): kotlin.String declared in <root>'
                 CONST String type=kotlin.String value="NOT_OK"
-          WHEN type=kotlin.Unit origin=IF
+          WHEN type=kotlin.Nothing origin=IF
             BRANCH
               if: GET_VAR 'x: kotlin.Boolean declared in <root>.run' type=kotlin.Boolean origin=null
               then: ERROR_EXPR 'Unbound loop: continue@@@[ERROR_EXPR(Cannot bind label l1 to a loop)] ' type=kotlin.Nothing
-          WHEN type=kotlin.Unit origin=IF
+          WHEN type=kotlin.Nothing origin=IF
             BRANCH
               if: GET_VAR 'y: kotlin.Boolean declared in <root>.run' type=kotlin.Boolean origin=null
               then: CONTINUE label=l2 loop.label=l2
diff --git a/compiler/testData/ir/irText/expressions/primitivesImplicitConversions.fir.txt b/compiler/testData/ir/irText/expressions/primitivesImplicitConversions.fir.txt
index 6057f7bbaba..6c9f4238d8d 100644
--- a/compiler/testData/ir/irText/expressions/primitivesImplicitConversions.fir.txt
+++ b/compiler/testData/ir/irText/expressions/primitivesImplicitConversions.fir.txt
@@ -59,11 +59,11 @@ FILE fqName:<root> fileName:/primitivesImplicitConversions.kt
   FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       VAR name:test1 type:kotlin.Int? [val]
-        CONST Int type=kotlin.Int? value=42
+        CONST Int type=kotlin.Int value=42
       VAR name:test2 type:kotlin.Long [val]
         CONST Int type=kotlin.Long value=42
       VAR name:test3 type:kotlin.Long? [val]
-        CONST Int type=kotlin.Long? value=42
+        CONST Int type=kotlin.Long value=42
       VAR name:test4 type:kotlin.Long? [val]
         CALL 'public final fun unaryMinus (): kotlin.Int declared in kotlin.Int' type=kotlin.Int origin=null
           $this: CONST Int type=kotlin.Int value=1
diff --git a/compiler/testData/ir/irText/expressions/safeAssignment.fir.txt b/compiler/testData/ir/irText/expressions/safeAssignment.fir.txt
index b86679a24a8..5d4dd9522c0 100644
--- a/compiler/testData/ir/irText/expressions/safeAssignment.fir.txt
+++ b/compiler/testData/ir/irText/expressions/safeAssignment.fir.txt
@@ -43,4 +43,4 @@ FILE fqName:<root> fileName:/safeAssignment.kt
     BLOCK_BODY
       SET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:x type:kotlin.Int visibility:private' type=kotlin.Unit origin=null
         receiver: GET_VAR 'nc: <root>.C? declared in <root>.test' type=<root>.C? origin=null
-        value: CONST Int type=kotlin.Int? value=42
+        value: CONST Int type=kotlin.Int value=42
diff --git a/compiler/testData/ir/irText/expressions/safeCalls.fir.txt b/compiler/testData/ir/irText/expressions/safeCalls.fir.txt
index 0071e2a9e8a..d0d4ab22ab7 100644
--- a/compiler/testData/ir/irText/expressions/safeCalls.fir.txt
+++ b/compiler/testData/ir/irText/expressions/safeCalls.fir.txt
@@ -85,7 +85,7 @@ FILE fqName:<root> fileName:/safeCalls.kt
     BLOCK_BODY
       SET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:value type:kotlin.Int visibility:private' type=kotlin.Unit origin=null
         receiver: GET_VAR 'x: <root>.Ref? declared in <root>.test4' type=<root>.Ref? origin=null
-        value: CONST Int type=kotlin.Int? value=0
+        value: CONST Int type=kotlin.Int value=0
   FUN name:test5 visibility:public modality:FINAL <> ($receiver:<root>.IHost, s:kotlin.String?) returnType:kotlin.Int?
     $receiver: VALUE_PARAMETER name:<this> type:<root>.IHost
     VALUE_PARAMETER name:s index:0 type:kotlin.String?
diff --git a/compiler/testData/ir/irText/expressions/smartCasts.fir.txt b/compiler/testData/ir/irText/expressions/smartCasts.fir.txt
index d6166c8c12a..2816e253721 100644
--- a/compiler/testData/ir/irText/expressions/smartCasts.fir.txt
+++ b/compiler/testData/ir/irText/expressions/smartCasts.fir.txt
@@ -38,7 +38,7 @@ FILE fqName:<root> fileName:/smartCasts.kt
   FUN name:test2 visibility:public modality:FINAL <> (x:kotlin.Any) returnType:kotlin.String
     VALUE_PARAMETER name:x index:0 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.String
             GET_VAR 'x: kotlin.Any declared in <root>.test2' type=kotlin.Any origin=null
@@ -50,7 +50,7 @@ FILE fqName:<root> fileName:/smartCasts.kt
   FUN name:test3 visibility:public modality:FINAL <> (x:kotlin.Any) returnType:kotlin.String
     VALUE_PARAMETER name:x index:0 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.String
             GET_VAR 'x: kotlin.Any declared in <root>.test3' type=kotlin.Any origin=null
diff --git a/compiler/testData/ir/irText/expressions/throw.fir.txt b/compiler/testData/ir/irText/expressions/throw.fir.txt
index ff79ded8a7a..b484f564470 100644
--- a/compiler/testData/ir/irText/expressions/throw.fir.txt
+++ b/compiler/testData/ir/irText/expressions/throw.fir.txt
@@ -6,7 +6,7 @@ FILE fqName:<root> fileName:/throw.kt
   FUN name:testImplicitCast visibility:public modality:FINAL <> (a:kotlin.Any) returnType:kotlin.Unit
     VALUE_PARAMETER name:a index:0 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.Nothing origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=INSTANCEOF typeOperand=kotlin.Throwable
             GET_VAR 'a: kotlin.Any declared in <root>.testImplicitCast' type=kotlin.Any origin=null
diff --git a/compiler/testData/ir/irText/expressions/tryCatchWithImplicitCast.fir.txt b/compiler/testData/ir/irText/expressions/tryCatchWithImplicitCast.fir.txt
index 2ceb0231314..9c2c32bbaed 100644
--- a/compiler/testData/ir/irText/expressions/tryCatchWithImplicitCast.fir.txt
+++ b/compiler/testData/ir/irText/expressions/tryCatchWithImplicitCast.fir.txt
@@ -10,7 +10,7 @@ FILE fqName:<root> fileName:/tryCatchWithImplicitCast.kt
             GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
       VAR name:t type:kotlin.String [val]
         TRY type=kotlin.String
-          try: GET_VAR 'a: kotlin.Any declared in <root>.testImplicitCast' type=kotlin.Any origin=null
+          try: GET_VAR 'a: kotlin.Any declared in <root>.testImplicitCast' type=kotlin.String origin=null
           CATCH parameter=val e: kotlin.Throwable [val] declared in <root>.testImplicitCast
             VAR name:e type:kotlin.Throwable [val]
             CONST String type=kotlin.String value=""
diff --git a/compiler/testData/ir/irText/expressions/useImportedMember.fir.txt b/compiler/testData/ir/irText/expressions/useImportedMember.fir.txt
index 40d196c57f4..89644a5da70 100644
--- a/compiler/testData/ir/irText/expressions/useImportedMember.fir.txt
+++ b/compiler/testData/ir/irText/expressions/useImportedMember.fir.txt
@@ -149,7 +149,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
       VALUE_PARAMETER name:g index:0 type:kotlin.String
   FUN name:box visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -159,7 +159,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST Int type=kotlin.Int value=1
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="1"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -169,7 +169,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST Int type=kotlin.Int value=2
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="2"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -178,7 +178,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST Int type=kotlin.Int value=3
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="3"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -190,7 +190,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
       SET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:p type:kotlin.Int visibility:private' type=kotlin.Unit origin=null
         receiver: GET_VAR '<this>: <root>.C declared in <root>.C' type=<root>.C origin=null
         value: CONST Int type=kotlin.Int value=5
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -199,7 +199,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST Int type=kotlin.Int value=5
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="5"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -208,7 +208,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST Int type=kotlin.Int value=6
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="6"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -219,7 +219,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST String type=kotlin.String value="7"
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="7"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -228,7 +228,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST String type=kotlin.String value="8"
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="8"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -238,7 +238,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST Int type=kotlin.Int value=9
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="9"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
@@ -247,7 +247,7 @@ FILE fqName:<root> fileName:/useImportedMember.kt
               arg1: CONST String type=kotlin.String value="10"
           then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
             CONST String type=kotlin.String value="10"
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.String origin=IF
         BRANCH
           if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
             $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
diff --git a/compiler/testData/ir/irText/expressions/varargWithImplicitCast.fir.txt b/compiler/testData/ir/irText/expressions/varargWithImplicitCast.fir.txt
index 3b93d65dfcb..62d4d450106 100644
--- a/compiler/testData/ir/irText/expressions/varargWithImplicitCast.fir.txt
+++ b/compiler/testData/ir/irText/expressions/varargWithImplicitCast.fir.txt
@@ -2,7 +2,7 @@ FILE fqName:<root> fileName:/varargWithImplicitCast.kt
   FUN name:testScalar visibility:public modality:FINAL <> (a:kotlin.Any) returnType:kotlin.IntArray
     VALUE_PARAMETER name:a index:0 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.IntArray origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.Int
             GET_VAR 'a: kotlin.Any declared in <root>.testScalar' type=kotlin.Any origin=null
@@ -14,7 +14,7 @@ FILE fqName:<root> fileName:/varargWithImplicitCast.kt
   FUN name:testSpread visibility:public modality:FINAL <> (a:kotlin.Any) returnType:kotlin.IntArray
     VALUE_PARAMETER name:a index:0 type:kotlin.Any
     BLOCK_BODY
-      WHEN type=kotlin.Unit origin=IF
+      WHEN type=kotlin.IntArray origin=IF
         BRANCH
           if: TYPE_OP type=kotlin.Boolean origin=NOT_INSTANCEOF typeOperand=kotlin.IntArray
             GET_VAR 'a: kotlin.Any declared in <root>.testSpread' type=kotlin.Any origin=null
diff --git a/compiler/testData/ir/irText/expressions/whenCoercedToUnit.fir.txt b/compiler/testData/ir/irText/expressions/whenCoercedToUnit.fir.txt
index da87de4dc9e..a1cba47a581 100644
--- a/compiler/testData/ir/irText/expressions/whenCoercedToUnit.fir.txt
+++ b/compiler/testData/ir/irText/expressions/whenCoercedToUnit.fir.txt
@@ -2,9 +2,9 @@ FILE fqName:<root> fileName:/whenCoercedToUnit.kt
   FUN name:foo visibility:public modality:FINAL <> (x:kotlin.Int) returnType:kotlin.Unit
     VALUE_PARAMETER name:x index:0 type:kotlin.Int
     BLOCK_BODY
-      BLOCK type=kotlin.Unit origin=WHEN
+      BLOCK type=kotlin.Int origin=WHEN
         VAR IR_TEMPORARY_VARIABLE name:tmp0_subject type:kotlin.Int [val]
-        WHEN type=kotlin.Unit origin=WHEN
+        WHEN type=kotlin.Int origin=WHEN
           BRANCH
             if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
               arg0: GET_VAR 'val tmp0_subject: kotlin.Int [val] declared in <root>.foo' type=kotlin.Int origin=null
diff --git a/compiler/testData/ir/irText/expressions/whileDoWhile.fir.txt b/compiler/testData/ir/irText/expressions/whileDoWhile.fir.txt
index decc70635ed..1940a72c661 100644
--- a/compiler/testData/ir/irText/expressions/whileDoWhile.fir.txt
+++ b/compiler/testData/ir/irText/expressions/whileDoWhile.fir.txt
@@ -71,4 +71,4 @@ FILE fqName:<root> fileName:/whileDoWhile.kt
               body: BLOCK type=kotlin.Unit origin=null
             DO_WHILE label=null origin=DO_WHILE_LOOP
               body: BLOCK type=kotlin.Unit origin=null
-              condition: GET_VAR 'val a: kotlin.Any? [val] declared in <root>.testSmartcastInCondition' type=kotlin.Any? origin=null
+              condition: GET_VAR 'val a: kotlin.Any? [val] declared in <root>.testSmartcastInCondition' type=kotlin.Boolean origin=null
diff --git a/compiler/testData/ir/irText/regressions/coercionInLoop.fir.txt b/compiler/testData/ir/irText/regressions/coercionInLoop.fir.txt
index f3d0683d9a6..65d1bbec938 100644
--- a/compiler/testData/ir/irText/regressions/coercionInLoop.fir.txt
+++ b/compiler/testData/ir/irText/regressions/coercionInLoop.fir.txt
@@ -13,7 +13,7 @@ FILE fqName:<root> fileName:/coercionInLoop.kt
         condition: CALL 'public abstract fun hasNext (): kotlin.Boolean declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=null
           $this: GET_VAR 'val x: kotlin.collections.DoubleIterator [val] declared in <root>.box' type=kotlin.collections.DoubleIterator origin=null
         body: BLOCK type=kotlin.Int origin=null
-          WHEN type=kotlin.Unit origin=IF
+          WHEN type=kotlin.String origin=IF
             BRANCH
               if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
                 $this: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
diff --git a/compiler/testData/ir/irText/regressions/kt24114.fir.txt b/compiler/testData/ir/irText/regressions/kt24114.fir.txt
index dc4e9d4ef00..56df4d12b33 100644
--- a/compiler/testData/ir/irText/regressions/kt24114.fir.txt
+++ b/compiler/testData/ir/irText/regressions/kt24114.fir.txt
@@ -11,16 +11,16 @@ FILE fqName:<root> fileName:/kt24114.kt
     BLOCK_BODY
       WHILE label=null origin=WHILE_LOOP
         condition: CONST Boolean type=kotlin.Boolean value=true
-        body: BLOCK type=kotlin.Unit origin=WHEN
+        body: BLOCK type=kotlin.Int origin=WHEN
           VAR IR_TEMPORARY_VARIABLE name:tmp0_subject type:kotlin.Int [val]
-          WHEN type=kotlin.Unit origin=WHEN
+          WHEN type=kotlin.Int origin=WHEN
             BRANCH
               if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
                 arg0: GET_VAR 'val tmp0_subject: kotlin.Int [val] declared in <root>.test1' type=kotlin.Int origin=null
                 arg1: CONST Int type=kotlin.Int value=1
-              then: BLOCK type=kotlin.Unit origin=WHEN
+              then: BLOCK type=kotlin.Int origin=WHEN
                 VAR IR_TEMPORARY_VARIABLE name:tmp1_subject type:kotlin.Int [val]
-                WHEN type=kotlin.Unit origin=WHEN
+                WHEN type=kotlin.Int origin=WHEN
                   BRANCH
                     if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
                       arg0: GET_VAR 'val tmp1_subject: kotlin.Int [val] declared in <root>.test1' type=kotlin.Int origin=null
@@ -35,16 +35,16 @@ FILE fqName:<root> fileName:/kt24114.kt
     BLOCK_BODY
       WHILE label=null origin=WHILE_LOOP
         condition: CONST Boolean type=kotlin.Boolean value=true
-        body: BLOCK type=kotlin.Unit origin=WHEN
+        body: BLOCK type=kotlin.Int origin=WHEN
           VAR IR_TEMPORARY_VARIABLE name:tmp2_subject type:kotlin.Int [val]
-          WHEN type=kotlin.Unit origin=WHEN
+          WHEN type=kotlin.Int origin=WHEN
             BRANCH
               if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
                 arg0: GET_VAR 'val tmp2_subject: kotlin.Int [val] declared in <root>.test2' type=kotlin.Int origin=null
                 arg1: CONST Int type=kotlin.Int value=1
-              then: BLOCK type=kotlin.Unit origin=WHEN
+              then: BLOCK type=kotlin.Int origin=WHEN
                 VAR IR_TEMPORARY_VARIABLE name:tmp3_subject type:kotlin.Int [val]
-                WHEN type=kotlin.Unit origin=WHEN
+                WHEN type=kotlin.Int origin=WHEN
                   BRANCH
                     if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
                       arg0: GET_VAR 'val tmp3_subject: kotlin.Int [val] declared in <root>.test2' type=kotlin.Int origin=null