diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithClassBefore.kt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithClassBefore.kt
new file mode 100644
index 000000000000..755bd66b40d2
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithClassBefore.kt
@@ -0,0 +1,5 @@
+class Foo<caret>() {
+    class c {}
+}
+
+// IGNORE_K1
\ No newline at end of file
diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithClassMessages.txt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithClassMessages.txt
new file mode 100644
index 000000000000..34d34a7b5735
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithClassMessages.txt
@@ -0,0 +1 @@
+Class 'c' is already declared in class 'Foo'
\ No newline at end of file
diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithFunctionAfter.kt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithFunctionAfter.kt
new file mode 100644
index 000000000000..f48288ec1636
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithFunctionAfter.kt
@@ -0,0 +1,3 @@
+class Foo(val f: () -> Unit) {
+    fun f() {}
+}
\ No newline at end of file
diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithFunctionBefore.kt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithFunctionBefore.kt
new file mode 100644
index 000000000000..33827020e7ff
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithFunctionBefore.kt
@@ -0,0 +1,3 @@
+class Foo<caret>() {
+    fun f() {}
+}
\ No newline at end of file
diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyBefore.kt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyBefore.kt
new file mode 100644
index 000000000000..74ad3f6cb404
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyBefore.kt
@@ -0,0 +1,3 @@
+class Foo<caret>() {
+    val p = 42
+}
\ No newline at end of file
diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyMessages.k2.txt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyMessages.k2.txt
new file mode 100644
index 000000000000..224759030113
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyMessages.k2.txt
@@ -0,0 +1 @@
+Property 'p' is already declared in class 'Foo'
\ No newline at end of file
diff --git a/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyMessages.txt b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyMessages.txt
new file mode 100644
index 000000000000..8331f5834275
--- /dev/null
+++ b/plugins/kotlin/idea/tests/testData/refactoring/changeSignature/AddValParameterToConstructorConflictWithPropertyMessages.txt
@@ -0,0 +1 @@
+Duplicating property 'p'
\ No newline at end of file
diff --git a/plugins/kotlin/refactorings/kotlin.refactorings.common.tests/test/org/jetbrains/kotlin/idea/refactoring/changeSignature/BaseKotlinChangeSignatureTest.kt b/plugins/kotlin/refactorings/kotlin.refactorings.common.tests/test/org/jetbrains/kotlin/idea/refactoring/changeSignature/BaseKotlinChangeSignatureTest.kt
index 0cb8a84edef4..1a3e2bcb17c0 100644
--- a/plugins/kotlin/refactorings/kotlin.refactorings.common.tests/test/org/jetbrains/kotlin/idea/refactoring/changeSignature/BaseKotlinChangeSignatureTest.kt
+++ b/plugins/kotlin/refactorings/kotlin.refactorings.common.tests/test/org/jetbrains/kotlin/idea/refactoring/changeSignature/BaseKotlinChangeSignatureTest.kt
@@ -1284,6 +1284,24 @@ abstract class BaseKotlinChangeSignatureTest<C: KotlinModifiableChangeInfo<P>, P
         newParameters[1].setType("Float?")
     }
 
+    fun testAddValParameterToConstructorConflictWithClass() = doTestConflict {
+        val parameter = createKotlinIntParameter("c")
+        parameter.valOrVar = KotlinValVar.Val
+        addParameter(parameter)
+    }
+
+    fun testAddValParameterToConstructorConflictWithProperty() = doTestConflict {
+        val parameter = createKotlinIntParameter("p")
+        parameter.valOrVar = KotlinValVar.Val
+        addParameter(parameter)
+    }
+
+    fun testAddValParameterToConstructorConflictWithFunction() = doTest {
+        val parameter = createKotlinParameter("f", "() -> Unit", null, false)
+        parameter.valOrVar = KotlinValVar.Val
+        addParameter(parameter)
+    }
+
     fun testGenericConstructor() = doTest {
         setNewVisibility(Public)
 
diff --git a/plugins/kotlin/refactorings/kotlin.refactorings.common/src/org/jetbrains/kotlin/idea/refactoring/conflicts/kotlinMembersNameConflicts.kt b/plugins/kotlin/refactorings/kotlin.refactorings.common/src/org/jetbrains/kotlin/idea/refactoring/conflicts/kotlinMembersNameConflicts.kt
index 5df9daef171c..e29948651d68 100644
--- a/plugins/kotlin/refactorings/kotlin.refactorings.common/src/org/jetbrains/kotlin/idea/refactoring/conflicts/kotlinMembersNameConflicts.kt
+++ b/plugins/kotlin/refactorings/kotlin.refactorings.common/src/org/jetbrains/kotlin/idea/refactoring/conflicts/kotlinMembersNameConflicts.kt
@@ -186,6 +186,23 @@ fun checkDeclarationNewNameConflicts(
     }
 }
 
+fun checkNewPropertyConflicts(
+    containingClass: KtClassOrObject,
+    newName: String,
+    result: MutableList<UsageInfo>,
+) {
+    analyze(containingClass) {
+        val containingSymbol = containingClass.getNamedClassOrObjectSymbol() ?: return
+        var potentialCandidates = containingSymbol
+            .getCombinedMemberScope()
+            .findSiblingsByName(containingSymbol, Name.identifier(newName), containingSymbol)
+            .filter { candidateSymbol -> candidateSymbol !is KtFunctionLikeSymbol }
+        for (candidateSymbol in potentialCandidates) {
+            registerAlreadyDeclaredConflict(candidateSymbol, result)
+        }
+    }
+}
+
 fun registerAlreadyDeclaredConflict(candidateSymbol: KtDeclarationSymbol, result: MutableList<UsageInfo>) {
     val candidate = candidateSymbol.psi as? PsiNamedElement ?: return
 
diff --git a/plugins/kotlin/refactorings/kotlin.refactorings.k2/src/org/jetbrains/kotlin/idea/k2/refactoring/changeSignature/KotlinChangeSignatureConflictSearcher.kt b/plugins/kotlin/refactorings/kotlin.refactorings.k2/src/org/jetbrains/kotlin/idea/k2/refactoring/changeSignature/KotlinChangeSignatureConflictSearcher.kt
index 1f3a3ae17cd1..e19dac9125fe 100644
--- a/plugins/kotlin/refactorings/kotlin.refactorings.k2/src/org/jetbrains/kotlin/idea/k2/refactoring/changeSignature/KotlinChangeSignatureConflictSearcher.kt
+++ b/plugins/kotlin/refactorings/kotlin.refactorings.k2/src/org/jetbrains/kotlin/idea/k2/refactoring/changeSignature/KotlinChangeSignatureConflictSearcher.kt
@@ -4,7 +4,6 @@ package org.jetbrains.kotlin.idea.k2.refactoring.changeSignature
 import com.intellij.openapi.util.Ref
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiNamedElement
-import com.intellij.psi.search.LocalSearchScope
 import com.intellij.psi.search.searches.ReferencesSearch
 import com.intellij.refactoring.changeSignature.JavaChangeSignatureUsageProcessor
 import com.intellij.refactoring.changeSignature.MethodCallUsageInfo
@@ -24,12 +23,13 @@ import org.jetbrains.kotlin.idea.k2.refactoring.changeSignature.usages.KotlinCha
 import org.jetbrains.kotlin.idea.k2.refactoring.changeSignature.usages.KotlinFunctionCallUsage
 import org.jetbrains.kotlin.idea.k2.refactoring.changeSignature.usages.KotlinOverrideUsageInfo
 import org.jetbrains.kotlin.idea.k2.refactoring.changeSignature.usages.KotlinPropertyCallUsage
+import org.jetbrains.kotlin.idea.refactoring.changeSignature.KotlinValVar
 import org.jetbrains.kotlin.idea.refactoring.conflicts.areSameSignatures
+import org.jetbrains.kotlin.idea.refactoring.conflicts.checkNewPropertyConflicts
 import org.jetbrains.kotlin.idea.refactoring.conflicts.checkRedeclarationConflicts
 import org.jetbrains.kotlin.idea.refactoring.conflicts.registerAlreadyDeclaredConflict
 import org.jetbrains.kotlin.idea.refactoring.conflicts.registerRetargetJobOnPotentialCandidates
 import org.jetbrains.kotlin.idea.refactoring.rename.BasicUnresolvableCollisionUsageInfo
-import org.jetbrains.kotlin.idea.references.KtDestructuringDeclarationReference
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
 import org.jetbrains.kotlin.psi.psiUtil.getQualifiedExpressionForSelector
@@ -70,9 +70,22 @@ class KotlinChangeSignatureConflictSearcher(
 
         for (parameter in originalInfo.getNonReceiverParameters()) {
 
-            if (parameter.oldName != parameter.name && !parameter.isNewParameter) {//todo conflicts with new parameter
+            if (parameter.oldName != parameter.name || parameter.isNewParameter) {
                 val unresolvableCollisions = mutableListOf<UsageInfo>()
-                checkRedeclarationConflicts(function.valueParameters[max(0, parameter.oldIndex - if (function.receiverTypeReference != null) 1 else 0)], parameter.name, unresolvableCollisions)
+                val ktParameter = if (!parameter.isNewParameter)
+                    function.valueParameters[max(0, parameter.oldIndex - if (function.receiverTypeReference != null) 1 else 0)]
+                else null
+                if (ktParameter != null) { //todo conflicts with new parameter
+                    checkRedeclarationConflicts(ktParameter, parameter.name, unresolvableCollisions)
+                }
+
+                if (function is KtConstructor<*> && parameter.valOrVar != KotlinValVar.None && !(ktParameter != null && ktParameter.hasValOrVar())) {
+
+                    val containingClass = function.containingClassOrObject
+                    if (containingClass != null) {
+                        checkNewPropertyConflicts(containingClass, parameter.name, unresolvableCollisions)
+                    }
+                }
                 for (info in unresolvableCollisions) {
                     when (info) {
                         is BasicUnresolvableCollisionUsageInfo -> {