diff --git a/compiler/testData/builtin-classes-kotlin.txt b/compiler/testData/builtin-classes-kotlin.txt
index bc4f558fa6c..c9f248c9a7f 100644
--- a/compiler/testData/builtin-classes-kotlin.txt
+++ b/compiler/testData/builtin-classes-kotlin.txt
@@ -674,10 +674,10 @@ public open class Throwable {
     public constructor Throwable(/*0*/ message: kotlin.String?)
     /*primary*/ public constructor Throwable(/*0*/ message: kotlin.String?, /*1*/ cause: kotlin.Throwable?)
     public constructor Throwable(/*0*/ cause: kotlin.Throwable?)
-    public final val cause: kotlin.Throwable?
-        public final fun <get-cause>(): kotlin.Throwable?
-    public final val message: kotlin.String?
-        public final fun <get-message>(): kotlin.String?
+    public open val cause: kotlin.Throwable?
+        public open fun <get-cause>(): kotlin.Throwable?
+    public open val message: kotlin.String?
+        public open fun <get-message>(): kotlin.String?
 }
 
 public object Unit {
diff --git a/compiler/testData/codegen/box/specialBuiltins/throwableImpl.kt b/compiler/testData/codegen/box/specialBuiltins/throwableImpl.kt
new file mode 100644
index 00000000000..2f6aeaa6b55
--- /dev/null
+++ b/compiler/testData/codegen/box/specialBuiltins/throwableImpl.kt
@@ -0,0 +1,21 @@
+class MyThrowable(message: String? = null, cause: Throwable? = null) : Throwable(message, cause) {
+
+    override val message: String?
+        get() = "My message: " + super.message
+
+    override val cause: Throwable?
+        get() = super.cause ?: this
+
+}
+
+fun box(): String {
+    try {
+        throw MyThrowable("test")
+    } catch (t: MyThrowable) {
+        if (t.cause != t) return "fail t.cause"
+        if (t.message != "My message: test") return "fail t.message"
+        return "OK"
+    }
+
+    return "fail: MyThrowable wasn't catched."
+}
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/ClassMembers.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/ClassMembers.txt
index 9f47baf99c4..7ac840e1926 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/ClassMembers.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/ClassMembers.txt
@@ -2,14 +2,14 @@ package test
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public final class E2 : java.lang.Exception {
     public constructor E2()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public/*package*/ open class JavaClass {
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/Constructor.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/Constructor.txt
index 18b5968f138..6629b496e2f 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/Constructor.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/Constructor.txt
@@ -2,14 +2,14 @@ package test
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public final class E2 : java.lang.Exception {
     public constructor E2()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public/*package*/ open class JavaClass {
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/DefaultArgs.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/DefaultArgs.txt
index ce72361ebee..83f59565e61 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/DefaultArgs.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/DefaultArgs.txt
@@ -4,8 +4,8 @@ package test
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public/*package*/ open class JavaClass {
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/Delegation.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/Delegation.txt
index abd2f085409..4e66a6e62d3 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/Delegation.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/Delegation.txt
@@ -2,14 +2,14 @@ package test
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public final class E2 : java.lang.Exception {
     public constructor E2()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public final class Impl : test.Trait {
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/GenericSubstitution.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/GenericSubstitution.txt
index e432b2bc225..6c2e57e3643 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/GenericSubstitution.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/GenericSubstitution.txt
@@ -11,8 +11,8 @@ public final class Derived : test.Base<kotlin.String> {
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public/*package*/ open class JavaClass {
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/TopLevel.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/TopLevel.txt
index ef46713b647..adc829404fb 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/TopLevel.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/TopLevel.txt
@@ -6,14 +6,14 @@ public fun two(): kotlin.Unit
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public final class E2 : java.lang.Exception {
     public constructor E2()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public/*package*/ open class JavaClass {
diff --git a/compiler/testData/compileJavaAgainstKotlin/method/throws/TraitMembers.txt b/compiler/testData/compileJavaAgainstKotlin/method/throws/TraitMembers.txt
index 370bc73dea0..ecebc4d9884 100644
--- a/compiler/testData/compileJavaAgainstKotlin/method/throws/TraitMembers.txt
+++ b/compiler/testData/compileJavaAgainstKotlin/method/throws/TraitMembers.txt
@@ -2,14 +2,14 @@ package test
 
 public final class E1 : java.lang.Exception {
     public constructor E1()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public final class E2 : java.lang.Exception {
     public constructor E2()
-    public final /*fake_override*/ val cause: kotlin.Throwable?
-    public final /*fake_override*/ val message: kotlin.String?
+    public open /*fake_override*/ val cause: kotlin.Throwable?
+    public open /*fake_override*/ val message: kotlin.String?
 }
 
 public/*package*/ open class JavaClass {
diff --git a/compiler/testData/diagnostics/tests/controlStructures/catchGenerics.txt b/compiler/testData/diagnostics/tests/controlStructures/catchGenerics.txt
index 5e3b067858b..55ddad66b6e 100644
--- a/compiler/testData/diagnostics/tests/controlStructures/catchGenerics.txt
+++ b/compiler/testData/diagnostics/tests/controlStructures/catchGenerics.txt
@@ -5,8 +5,8 @@ public inline fun </*0*/ reified E : java.lang.Exception, /*1*/ R> tryCatch(/*0*
 
 public final class XException</*0*/ T> : kotlin.Throwable {
     public constructor XException</*0*/ T>(/*0*/ p: T)
-    public final override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
-    public final override /*1*/ /*fake_override*/ val message: kotlin.String?
+    public open override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
+    public open override /*1*/ /*fake_override*/ val message: kotlin.String?
     public final val p: T
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
@@ -15,8 +15,8 @@ public final class XException</*0*/ T> : kotlin.Throwable {
 
 public final class YException</*0*/ T> : java.lang.RuntimeException {
     public constructor YException</*0*/ T>(/*0*/ p: T)
-    public final override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
-    public final override /*1*/ /*fake_override*/ val message: kotlin.String?
+    public open override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
+    public open override /*1*/ /*fake_override*/ val message: kotlin.String?
     public final val p: T
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
@@ -25,8 +25,8 @@ public final class YException</*0*/ T> : java.lang.RuntimeException {
 
 public final class ZException</*0*/ T> : java.lang.Exception {
     public constructor ZException</*0*/ T>(/*0*/ p: T)
-    public final override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
-    public final override /*1*/ /*fake_override*/ val message: kotlin.String?
+    public open override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
+    public open override /*1*/ /*fake_override*/ val message: kotlin.String?
     public final val p: T
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
diff --git a/compiler/testData/diagnostics/tests/regressions/kt498.txt b/compiler/testData/diagnostics/tests/regressions/kt498.txt
index f4cb87a3793..048a01821e5 100644
--- a/compiler/testData/diagnostics/tests/regressions/kt498.txt
+++ b/compiler/testData/diagnostics/tests/regressions/kt498.txt
@@ -4,8 +4,8 @@ public fun </*0*/ T : kotlin.Any> T.getJavaClass(): java.lang.Class<T>
 
 public final class IdUnavailableException : java.lang.Exception {
     public constructor IdUnavailableException()
-    public final override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
-    public final override /*1*/ /*fake_override*/ val message: kotlin.String?
+    public open override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
+    public open override /*1*/ /*fake_override*/ val message: kotlin.String?
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/testData/diagnostics/tests/smartCasts/varnotnull/initInTryReturnInCatch.txt b/compiler/testData/diagnostics/tests/smartCasts/varnotnull/initInTryReturnInCatch.txt
index 917a26e2ab0..595083eed75 100644
--- a/compiler/testData/diagnostics/tests/smartCasts/varnotnull/initInTryReturnInCatch.txt
+++ b/compiler/testData/diagnostics/tests/smartCasts/varnotnull/initInTryReturnInCatch.txt
@@ -9,8 +9,8 @@ public fun test6(): kotlin.Unit
 
 public final class A : java.lang.Exception {
     public constructor A()
-    public final override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
-    public final override /*1*/ /*fake_override*/ val message: kotlin.String?
+    public open override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
+    public open override /*1*/ /*fake_override*/ val message: kotlin.String?
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
@@ -18,8 +18,8 @@ public final class A : java.lang.Exception {
 
 public final class B : java.lang.Exception {
     public constructor B()
-    public final override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
-    public final override /*1*/ /*fake_override*/ val message: kotlin.String?
+    public open override /*1*/ /*fake_override*/ val cause: kotlin.Throwable?
+    public open override /*1*/ /*fake_override*/ val message: kotlin.String?
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java
index feff112f481..51df8e3387c 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java
@@ -7492,6 +7492,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("throwableImpl.kt")
+        public void testThrowableImpl() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/specialBuiltins/throwableImpl.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("valuesInsideEnum.kt")
         public void testValuesInsideEnum() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/specialBuiltins/valuesInsideEnum.kt");
diff --git a/core/builtins/native/kotlin/Throwable.kt b/core/builtins/native/kotlin/Throwable.kt
index 7a38d638692..ceda70568bf 100644
--- a/core/builtins/native/kotlin/Throwable.kt
+++ b/core/builtins/native/kotlin/Throwable.kt
@@ -22,7 +22,7 @@ package kotlin
  * @param message the detail message string.
  * @param cause the cause of this throwable.
  */
-public open class Throwable(val message: String?, val cause: Throwable?) {
+public open class Throwable(open val message: String?, open val cause: Throwable?) {
     constructor(message: String?) : this(message, null)
 
     constructor(cause: Throwable?) : this(cause?.toString(), cause)