diff --git a/compiler/fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt b/compiler/fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
index a01ea6be93c..852bb3106ae 100644
--- a/compiler/fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
+++ b/compiler/fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
@@ -384,11 +384,19 @@ class RawFirBuilder(val session: FirSession, val stubMode: Boolean) {
                     superTypeCallEntry?.extractArgumentsTo(this)
                 }
             }
+
+            fun defaultVisibility() =
+                if (owner is KtObjectDeclaration || owner.hasModifier(SEALED_KEYWORD) || owner.hasModifier(ENUM_KEYWORD))
+                // TODO: sealed is FILE_PRIVATE (?) object / enum is HIDDEN (?)
+                    Visibilities.PRIVATE
+                else
+                    Visibilities.UNKNOWN
+
             val firConstructor = FirPrimaryConstructorImpl(
                 session,
                 this ?: owner,
                 FirFunctionSymbol(callableIdForClassConstructor()),
-                this?.visibility ?: Visibilities.UNKNOWN,
+                this?.visibility ?: defaultVisibility(),
                 this?.hasExpectModifier() ?: false,
                 this?.hasActualModifier() ?: false,
                 delegatedSelfTypeRef,
diff --git a/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums.txt b/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums.txt
index eb8df5b168f..4e74cfbef4e 100644
--- a/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums.txt
+++ b/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums.txt
@@ -1,6 +1,6 @@
 FILE: enums.kt
     public? final? enum class Order : kotlin/Enum {
-        public? constructor(): super<kotlin/Enum>()
+        private constructor(): super<kotlin/Enum>()
 
         public? final enum entry FIRST : kotlin/Any {
             public? constructor(): super<kotlin/Any>()
@@ -60,7 +60,7 @@ FILE: enums.kt
         public? abstract fun sayHello(): kotlin/Unit
 
         public? final? companion object Companion : kotlin/Any {
-            public? constructor(): super<kotlin/Any>()
+            private constructor(): super<kotlin/Any>()
 
             public? final? const val G: <implicit> = Double(6.67E-11)
                 public? get(): <implicit>
diff --git a/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums2.txt b/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums2.txt
index cfb0af99105..7234efaf48a 100644
--- a/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums2.txt
+++ b/compiler/fir/psi2fir/testData/rawBuilder/declarations/enums2.txt
@@ -2,11 +2,11 @@ FILE: enums2.kt
     public? final? interface Some : kotlin/Any {
     }
     public? final? object O1 : Some {
-        public? constructor(): super<kotlin/Any>()
+        private constructor(): super<kotlin/Any>()
 
     }
     public? final? object O2 : Some {
-        public? constructor(): super<kotlin/Any>()
+        private constructor(): super<kotlin/Any>()
 
     }
     public? final? enum class SomeEnum : kotlin/Enum {
diff --git a/compiler/fir/psi2fir/testData/rawBuilder/declarations/nestedClass.txt b/compiler/fir/psi2fir/testData/rawBuilder/declarations/nestedClass.txt
index 7802a8ad7b8..20373284004 100644
--- a/compiler/fir/psi2fir/testData/rawBuilder/declarations/nestedClass.txt
+++ b/compiler/fir/psi2fir/testData/rawBuilder/declarations/nestedClass.txt
@@ -15,7 +15,7 @@ FILE: nestedClass.kt
         }
 
         public? final? object Obj : Base {
-            public? constructor(): super<Base>(String())
+            private constructor(): super<Base>(String())
 
         }
 
diff --git a/compiler/fir/psi2fir/testData/rawBuilder/expressions/locals.txt b/compiler/fir/psi2fir/testData/rawBuilder/expressions/locals.txt
index bcd2906d6ee..0ab4aae69cf 100644
--- a/compiler/fir/psi2fir/testData/rawBuilder/expressions/locals.txt
+++ b/compiler/fir/psi2fir/testData/rawBuilder/expressions/locals.txt
@@ -18,7 +18,7 @@ FILE: locals.kt
         }
 
         lval code: <implicit> = object : Any {
-            public? constructor(): super<Any>()
+            private constructor(): super<Any>()
 
             public? final? fun foo(): <implicit> {
                 ^foo hashCode#()
diff --git a/compiler/fir/resolve/testData/resolve/companion.txt b/compiler/fir/resolve/testData/resolve/companion.txt
index ad95d0f8e86..a3cab174d5f 100644
--- a/compiler/fir/resolve/testData/resolve/companion.txt
+++ b/compiler/fir/resolve/testData/resolve/companion.txt
@@ -3,7 +3,7 @@ FILE: companion.kt
         public constructor(): super<R|kotlin/Any|>()
 
         public final companion object Companion : R|kotlin/Any| {
-            public constructor(): super<R|kotlin/Any|>()
+            private constructor(): super<R|kotlin/Any|>()
 
             public final class InCompanion : R|kotlin/Any| {
                 public constructor(): super<R|kotlin/Any|>()
@@ -20,7 +20,7 @@ FILE: companion.kt
         public constructor(): super<R|kotlin/Any|>()
 
         public final companion object NamedCompanion : R|kotlin/Any| {
-            public constructor(): super<R|kotlin/Any|>()
+            private constructor(): super<R|kotlin/Any|>()
 
             public final class InCompanion : R|kotlin/Any| {
                 public constructor(): super<R|kotlin/Any|>()
diff --git a/compiler/fir/resolve/testData/resolve/enum.txt b/compiler/fir/resolve/testData/resolve/enum.txt
index b0f10aed59e..0569cff0ca2 100644
--- a/compiler/fir/resolve/testData/resolve/enum.txt
+++ b/compiler/fir/resolve/testData/resolve/enum.txt
@@ -2,11 +2,11 @@ FILE: enum.kt
     public abstract interface Some : R|kotlin/Any| {
     }
     public final object O1 : R|Some| {
-        public constructor(): super<R|kotlin/Any|>()
+        private constructor(): super<R|kotlin/Any|>()
 
     }
     public final object O2 : R|Some| {
-        public constructor(): super<R|kotlin/Any|>()
+        private constructor(): super<R|kotlin/Any|>()
 
     }
     public final enum class SomeEnum : R|kotlin/Enum| {
diff --git a/compiler/fir/resolve/testData/resolve/expresssions/localImplicitBodies.txt b/compiler/fir/resolve/testData/resolve/expresssions/localImplicitBodies.txt
index b36f39aae2b..b9b95d9c34c 100644
--- a/compiler/fir/resolve/testData/resolve/expresssions/localImplicitBodies.txt
+++ b/compiler/fir/resolve/testData/resolve/expresssions/localImplicitBodies.txt
@@ -1,7 +1,7 @@
 FILE: localImplicitBodies.kt
     public final fun foo(): R|kotlin/Unit| {
         lval x: <ERROR TYPE REF: No result type for initializer> = object : R|kotlin/Any| {
-            public constructor(): super<R|kotlin/Any|>()
+            private constructor(): super<R|kotlin/Any|>()
 
             public final fun sss(): <ERROR TYPE REF: Unresolved name: abc> {
                 ^sss <Unresolved name: abc>#()
diff --git a/compiler/fir/resolve/testData/resolve/fromBuilder/enums.txt b/compiler/fir/resolve/testData/resolve/fromBuilder/enums.txt
index a84bbf590a2..7f9b5c74fcc 100644
--- a/compiler/fir/resolve/testData/resolve/fromBuilder/enums.txt
+++ b/compiler/fir/resolve/testData/resolve/fromBuilder/enums.txt
@@ -60,7 +60,7 @@ FILE: enums.kt
         public abstract fun sayHello(): R|kotlin/Unit|
 
         public final companion object Companion : R|kotlin/Any| {
-            public constructor(): super<R|kotlin/Any|>()
+            private constructor(): super<R|kotlin/Any|>()
 
             public final const val G: R|kotlin/Double| = Double(6.67E-11)
                 public get(): R|kotlin/Double|
diff --git a/compiler/fir/resolve/testData/resolve/nestedClass.txt b/compiler/fir/resolve/testData/resolve/nestedClass.txt
index c2716f33ddf..1827e8a2ee8 100644
--- a/compiler/fir/resolve/testData/resolve/nestedClass.txt
+++ b/compiler/fir/resolve/testData/resolve/nestedClass.txt
@@ -15,7 +15,7 @@ FILE: nestedClass.kt
         }
 
         public final object Obj : R|Base| {
-            public constructor(): super<R|Base|>(String())
+            private constructor(): super<R|Base|>(String())
 
         }