diff --git a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt
index bf545b309f2..4515acc454a 100644
--- a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt
+++ b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt
@@ -643,7 +643,12 @@ class DeclarationsConverter(
                     )
                     superTypeRefs += enumClassWrapper.delegatedSuperTypeRef
                     convertPrimaryConstructor(null, null, enumClassWrapper, null)?.let { declarations += it.firConstructor }
-                    classBodyNode?.also { declarations += convertClassBody(it, enumClassWrapper) }
+                    classBodyNode?.also {
+                        // Use ANONYMOUS_OBJECT_NAME for the owner class id of enum entry declarations
+                        withChildClassName(ANONYMOUS_OBJECT_NAME, isLocal = true) {
+                            declarations += convertClassBody(it, enumClassWrapper)
+                        }
+                    }
                 }
             }
         }
diff --git a/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt b/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
index 7fd8158136e..fb3a17049bb 100644
--- a/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
+++ b/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
@@ -761,14 +761,17 @@ class RawFirBuilder(
                             owner = ktEnumEntry,
                             typeParameters
                         )
-                        for (declaration in ktEnumEntry.declarations) {
-                            declarations += declaration.toFirDeclaration(
-                                correctedEnumSelfTypeRef,
-                                delegatedSelfType = delegatedEntrySelfType,
-                                ktEnumEntry,
-                                ownerClassBuilder = this,
-                                ownerTypeParameters = emptyList()
-                            )
+                        // Use ANONYMOUS_OBJECT_NAME for the owner class id for enum entry declarations (see KT-42351)
+                        withChildClassName(ANONYMOUS_OBJECT_NAME, isLocal = true) {
+                            for (declaration in ktEnumEntry.declarations) {
+                                declarations += declaration.toFirDeclaration(
+                                    correctedEnumSelfTypeRef,
+                                    delegatedSelfType = delegatedEntrySelfType,
+                                    ktEnumEntry,
+                                    ownerClassBuilder = this,
+                                    ownerTypeParameters = emptyList()
+                                )
+                            }
                         }
                     }
                 }
diff --git a/compiler/testData/codegen/box/enum/enumEntryMembers.kt b/compiler/testData/codegen/box/enum/enumEntryMembers.kt
index 919960c4463..0747281c05e 100644
--- a/compiler/testData/codegen/box/enum/enumEntryMembers.kt
+++ b/compiler/testData/codegen/box/enum/enumEntryMembers.kt
@@ -3,6 +3,10 @@
 // FILE: lib.kt
 enum class Foo {
     FOO() {
+        // Test for KT-42351
+        private fun privateBar() = "bar"
+        override fun bar(): String = privateBar()
+
         override fun foo() = "foo"
        
         override var xxx: String
@@ -12,6 +16,7 @@ enum class Foo {
     };
 
     abstract fun foo(): String
+    abstract fun bar(): String
     abstract var xxx: String
 }
 
@@ -25,6 +30,7 @@ fun box(): String {
     assertEquals(Foo.FOO.xxx, "xxx")
     assertEquals(Foo.FOO.toString(), "FOO")
     assertEquals(Foo.valueOf("FOO").toString(), "FOO")
+    assertEquals(Foo.FOO.bar(), "bar")
     return "OK"
 }