diff --git a/compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmClosureGenerationScheme.kt b/compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmClosureGenerationScheme.kt
index 70d950979a5..a03ab246059 100644
--- a/compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmClosureGenerationScheme.kt
+++ b/compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmClosureGenerationScheme.kt
@@ -17,7 +17,9 @@ enum class JvmClosureGenerationScheme(
         val DEFAULT = CLASS
 
         @JvmStatic
-        fun fromString(string: String?) =
-            values().find { it.description == string }
+        fun fromString(string: String?): JvmClosureGenerationScheme? {
+            val lowerStr = string?.toLowerCase() ?: return null
+            return values().find { it.description == lowerStr }
+        }
     }
 }
\ No newline at end of file
diff --git a/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericFunInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericFunInterface.kt
index 5686fc2bcb1..a2d47698ac1 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericFunInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericFunInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericSamInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericSamInterface.kt
index 0e255f086a2..ba84bcee015 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericSamInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/callableRefGenericSamInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedFunInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedFunInterface.kt
index 163b33e639e..7f660ec5ac6 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedFunInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedFunInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedSamInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedSamInterface.kt
index d403207631f..40aa971bbd2 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedSamInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/callableRefSpecializedSamInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/genericFunInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/genericFunInterface.kt
index f41de2181c4..da1d072138c 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/genericFunInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/genericFunInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/genericSamInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/genericSamInterface.kt
index edbb878fe04..94cb400b9c0 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/genericSamInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/genericSamInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/kt16650.kt b/compiler/testData/codegen/bytecodeListing/sam/kt16650.kt
index 8a0e7b6a313..1226b92332f 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/kt16650.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/kt16650.kt
@@ -1,4 +1,4 @@
-// SAM_CONVERSIONS: CLASS
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 fun main(x: DataStream<Int>) {
diff --git a/compiler/testData/codegen/bytecodeListing/sam/kt16650_ir.txt b/compiler/testData/codegen/bytecodeListing/sam/kt16650_ir.txt
index 1b1bb19c3cc..50b30869177 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/kt16650_ir.txt
+++ b/compiler/testData/codegen/bytecodeListing/sam/kt16650_ir.txt
@@ -1,7 +1,31 @@
+@kotlin.Metadata
+final class<<IN:Ljava/lang/Object;KEY:Ljava/lang/Object;>Ljava/lang/Object;LKeySelector<Ljava/lang/Integer;Ljava/lang/Long;>;>  TKt$main$1 {
+    // source: 't.kt'
+    static <null> method <clinit>(): void
+    <null> method <init>(): void
+    public final <null> method getKey(p0: java.lang.Integer): java.lang.Long
+    public synthetic bridge <null> method getKey(p0: java.lang.Object): java.lang.Object
+    enclosing method TKt.main(LDataStream;)V
+    public final static field <LTKt$main$1<TIN;TKEY;>;> INSTANCE: TKt$main$1
+    inner (anonymous) class TKt$main$1
+}
+
+@kotlin.Metadata
+final class<<IN:Ljava/lang/Object;KEY:Ljava/lang/Object;>Ljava/lang/Object;LKeySelector<Ljava/lang/Integer;Ljava/lang/Long;>;>  TKt$main$2 {
+    // source: 't.kt'
+    static <null> method <clinit>(): void
+    <null> method <init>(): void
+    public final <null> method getKey(p0: java.lang.Integer): java.lang.Long
+    public synthetic bridge <null> method getKey(p0: java.lang.Object): java.lang.Object
+    enclosing method TKt.main(LDataStream;)V
+    public final static field <LTKt$main$2<TIN;TKEY;>;> INSTANCE: TKt$main$2
+    inner (anonymous) class TKt$main$2
+}
+
 @kotlin.Metadata
 public final class<null>  TKt {
     // source: 't.kt'
     public final static <(LDataStream<Ljava/lang/Integer;>;)V> method main(@org.jetbrains.annotations.NotNull p0: DataStream): void
-    private final static <null> method main$lambda-0(p0: java.lang.Integer): java.lang.Long
-    private final static <null> method main$lambda-1(p0: java.lang.Integer): java.lang.Long
+    inner (anonymous) class TKt$main$1
+    inner (anonymous) class TKt$main$2
 }
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface.kt
index e06a76011af..905fe074852 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface_ir.txt b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface_ir.txt
index 06aebcc78e9..58ebc83375c 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface_ir.txt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericFunInterface_ir.txt
@@ -4,10 +4,20 @@ public interface<<T:Ljava/lang/Object;>Ljava/lang/Object;>  Sam {
     public abstract <()TT;> method get(): java.lang.Object
 }
 
+@kotlin.Metadata
+final class<<T:Ljava/lang/Object;>Ljava/lang/Object;LSam<TT;>;>  TKt$genericSamGet$1 {
+    // source: 't.kt'
+    public final <()TT;> method get(): java.lang.Object
+    <(Lkotlin/jvm/functions/Function0<+TT;>;)V> method <init>(p0: kotlin.jvm.functions.Function0): void
+    enclosing method TKt.genericSamGet(Lkotlin/jvm/functions/Function0;)Ljava/lang/Object;
+    synthetic final field <Lkotlin/jvm/functions/Function0<TT;>;> $f: kotlin.jvm.functions.Function0
+    inner (anonymous) class TKt$genericSamGet$1
+}
+
 @kotlin.Metadata
 public final class<null>  TKt {
     // source: 't.kt'
     public final static <<T:Ljava/lang/Object;>(LSam<TT;>;)TT;> method expectsSam(@org.jetbrains.annotations.NotNull p0: Sam): java.lang.Object
-    private final static <<T:Ljava/lang/Object;>(Lkotlin/jvm/functions/Function0<+TT;>;)TT;> method genericSamGet$lambda-0(p0: kotlin.jvm.functions.Function0): java.lang.Object
     public final static <<T:Ljava/lang/Object;>(Lkotlin/jvm/functions/Function0<+TT;>;)TT;> method genericSamGet(@org.jetbrains.annotations.NotNull p0: kotlin.jvm.functions.Function0): java.lang.Object
+    inner (anonymous) class TKt$genericSamGet$1
 }
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface.kt
index 9720eeec38e..7b378b3679a 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface_ir.txt b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface_ir.txt
index 7c5f65a0533..023cc600dfa 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface_ir.txt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaGenericSamInterface_ir.txt
@@ -1,8 +1,28 @@
+@kotlin.Metadata
+final class<<T:Ljava/lang/Object;>Ljava/lang/Object;LSam<TT;>;>  TKt$genericSam$1 {
+    // source: 't.kt'
+    public final <()TT;> method get(): java.lang.Object
+    <(Lkotlin/jvm/functions/Function0<+TT;>;)V> method <init>(p0: kotlin.jvm.functions.Function0): void
+    enclosing method TKt.genericSam(Lkotlin/jvm/functions/Function0;)LSam;
+    synthetic final field <Lkotlin/jvm/functions/Function0<TT;>;> $f: kotlin.jvm.functions.Function0
+    inner (anonymous) class TKt$genericSam$1
+}
+
+@kotlin.Metadata
+final class<<T:Ljava/lang/Object;>Ljava/lang/Object;LSam<TT;>;>  TKt$genericSamGet$1 {
+    // source: 't.kt'
+    public final <()TT;> method get(): java.lang.Object
+    <(Lkotlin/jvm/functions/Function0<+TT;>;)V> method <init>(p0: kotlin.jvm.functions.Function0): void
+    enclosing method TKt.genericSamGet(Lkotlin/jvm/functions/Function0;)Ljava/lang/Object;
+    synthetic final field <Lkotlin/jvm/functions/Function0<TT;>;> $f: kotlin.jvm.functions.Function0
+    inner (anonymous) class TKt$genericSamGet$1
+}
+
 @kotlin.Metadata
 public final class<null>  TKt {
     // source: 't.kt'
     public final static @org.jetbrains.annotations.NotNull <<T:Ljava/lang/Object;>(Lkotlin/jvm/functions/Function0<+TT;>;)LSam<TT;>;> method genericSam(@org.jetbrains.annotations.NotNull p0: kotlin.jvm.functions.Function0): Sam
-    private final static <<T:Ljava/lang/Object;>(Lkotlin/jvm/functions/Function0<+TT;>;)TT;> method genericSam$lambda-0(p0: kotlin.jvm.functions.Function0): java.lang.Object
-    private final static <<T:Ljava/lang/Object;>(Lkotlin/jvm/functions/Function0<+TT;>;)TT;> method genericSamGet$lambda-1(p0: kotlin.jvm.functions.Function0): java.lang.Object
     public final static <<T:Ljava/lang/Object;>(Lkotlin/jvm/functions/Function0<+TT;>;)TT;> method genericSamGet(@org.jetbrains.annotations.NotNull p0: kotlin.jvm.functions.Function0): java.lang.Object
+    inner (anonymous) class TKt$genericSam$1
+    inner (anonymous) class TKt$genericSamGet$1
 }
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface.kt
index 7cb672329d5..1ef76184990 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface.kt
@@ -1,4 +1,4 @@
-
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface_ir.txt b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface_ir.txt
index 9d30b5549c0..8020d43de86 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface_ir.txt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedFunInterface_ir.txt
@@ -4,10 +4,21 @@ public interface<<T:Ljava/lang/Object;>Ljava/lang/Object;>  Sam {
     public abstract <()TT;> method get(): java.lang.Object
 }
 
+@kotlin.Metadata
+final class<<T:Ljava/lang/Object;>Ljava/lang/Object;LSam<Ljava/lang/String;>;>  TKt$specializedSam$1 {
+    // source: 't.kt'
+    <(Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;)V> method <init>(p0: kotlin.jvm.functions.Function0): void
+    public synthetic bridge <null> method get(): java.lang.Object
+    public final @org.jetbrains.annotations.NotNull <null> method get(): java.lang.String
+    enclosing method TKt.specializedSam(Lkotlin/jvm/functions/Function0;)Ljava/lang/String;
+    synthetic final field <Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;> $f: kotlin.jvm.functions.Function0
+    inner (anonymous) class TKt$specializedSam$1
+}
+
 @kotlin.Metadata
 public final class<null>  TKt {
     // source: 't.kt'
-    private final static <(Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;)Ljava/lang/String;> method specializedSam$lambda-0(p0: kotlin.jvm.functions.Function0): java.lang.String
     public final static @org.jetbrains.annotations.NotNull <(Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;)Ljava/lang/String;> method specializedSam(@org.jetbrains.annotations.NotNull p0: kotlin.jvm.functions.Function0): java.lang.String
     public final static <<T:Ljava/lang/Object;>(LSam<TT;>;)TT;> method expectsSam(@org.jetbrains.annotations.NotNull p0: Sam): java.lang.Object
+    inner (anonymous) class TKt$specializedSam$1
 }
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface.kt
index 185c15d0e83..16a96f79fb6 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface_ir.txt b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface_ir.txt
index 6274ccb7d0b..9333ea1d30f 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface_ir.txt
+++ b/compiler/testData/codegen/bytecodeListing/sam/lambdaSpecializedSamInterface_ir.txt
@@ -1,6 +1,17 @@
+@kotlin.Metadata
+final class<<T:Ljava/lang/Object;>Ljava/lang/Object;LSam<Ljava/lang/String;>;>  TKt$specializedSam$1 {
+    // source: 't.kt'
+    <(Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;)V> method <init>(p0: kotlin.jvm.functions.Function0): void
+    public synthetic bridge <null> method get(): java.lang.Object
+    public final <null> method get(): java.lang.String
+    enclosing method TKt.specializedSam(Lkotlin/jvm/functions/Function0;)Ljava/lang/String;
+    synthetic final field <Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;> $f: kotlin.jvm.functions.Function0
+    inner (anonymous) class TKt$specializedSam$1
+}
+
 @kotlin.Metadata
 public final class<null>  TKt {
     // source: 't.kt'
-    private final static <(Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;)Ljava/lang/String;> method specializedSam$lambda-0(p0: kotlin.jvm.functions.Function0): java.lang.String
     public final static <(Lkotlin/jvm/functions/Function0<Ljava/lang/String;>;)Ljava/lang/String;> method specializedSam(@org.jetbrains.annotations.NotNull p0: kotlin.jvm.functions.Function0): java.lang.String
+    inner (anonymous) class TKt$specializedSam$1
 }
diff --git a/compiler/testData/codegen/bytecodeListing/sam/reusedSamWrapperClasses.kt b/compiler/testData/codegen/bytecodeListing/sam/reusedSamWrapperClasses.kt
index 9db99e321b9..536a27e6b15 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/reusedSamWrapperClasses.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/reusedSamWrapperClasses.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_RUNTIME
 
 class A {
diff --git a/compiler/testData/codegen/bytecodeListing/sam/samAdapterAndInlinedOne.kt b/compiler/testData/codegen/bytecodeListing/sam/samAdapterAndInlinedOne.kt
index 5fb0edbf713..8aac7428cfe 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/samAdapterAndInlinedOne.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/samAdapterAndInlinedOne.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 package test
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/specializedFunInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/specializedFunInterface.kt
index 150cd5d58d4..29fe54748b5 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/specializedFunInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/specializedFunInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/specializedSamInterface.kt b/compiler/testData/codegen/bytecodeListing/sam/specializedSamInterface.kt
index 72ecaa94f56..47b7a58da68 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/specializedSamInterface.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/specializedSamInterface.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 // WITH_SIGNATURES
 // FILE: t.kt
 
diff --git a/compiler/testData/codegen/bytecodeListing/sam/wrapperInlinedFromAnotherClass.kt b/compiler/testData/codegen/bytecodeListing/sam/wrapperInlinedFromAnotherClass.kt
index dadc316c73e..77b7431c89a 100644
--- a/compiler/testData/codegen/bytecodeListing/sam/wrapperInlinedFromAnotherClass.kt
+++ b/compiler/testData/codegen/bytecodeListing/sam/wrapperInlinedFromAnotherClass.kt
@@ -1,3 +1,4 @@
+// KOTLIN_CONFIGURATION_FLAGS: SAM_CONVERSIONS=CLASS
 class A {
     fun test1a() = B().runnable1()
     fun test1b() = B().runnable1()