diff --git a/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/KDocConfig.kt b/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/KDocConfig.kt
index fa6935c3461..0561dbf6e90 100644
--- a/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/KDocConfig.kt
+++ b/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/KDocConfig.kt
@@ -27,12 +27,13 @@ class KDocConfig() {
      * Returns a map of the package prefix to the HTML URL for the root of the apidoc using javadoc/kdoc style
      * directory layouts so that this API doc report can link to external packages
      */
-    public val packagePrefixToUrls: Map<String, String> = TreeMap<String, String>(LongestFirstStringComparator())
+    private val mutablePackagePrefixToUrls: MutableMap<String, String> = TreeMap<String, String>(LongestFirstStringComparator())
+    public val packagePrefixToUrls: Map<String, String> = mutablePackagePrefixToUrls
 
     /**
      * Returns a Set of the package name prefixes to ignore from the KDoc report
      */
-    public val ignorePackages: Set<String> = HashSet<String>()
+    public val ignorePackages: MutableSet<String> = HashSet<String>()
 
     /**
     * Returns true if a warning should be generated if there are no comments
@@ -75,14 +76,15 @@ class KDocConfig() {
     /**
      * Returns a set of all the package which have been warned that were missing an external URL
      */
-    public val missingPackageUrls: Set<String> = TreeSet<String>()
+    private val mutableMissingPackageUrls: MutableSet<String> = TreeSet<String>()
+    public val missingPackageUrls: Set<String> = mutableMissingPackageUrls
 
     /**
      * Adds one or more package prefixes to the given javadoc URL
      */
     fun addPackageLink(url: String, vararg packagePrefixes: String): Unit {
         for (p in packagePrefixes) {
-            packagePrefixToUrls.put(p, url)
+            mutablePackagePrefixToUrls.put(p, url)
         }
     }
 
@@ -97,7 +99,7 @@ class KDocConfig() {
                 return url
             }
        }
-        if (warn && missingPackageUrls.add(packageName)) {
+        if (warn && mutableMissingPackageUrls.add(packageName)) {
             println("Warning: could not find external link to package: $packageName")
         }
         return ""
diff --git a/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt b/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt
index e8fe23211b1..07a32e5fdba 100644
--- a/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt
+++ b/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt
@@ -438,7 +438,7 @@ class KModel(val context: BindingContext, val config: KDocConfig, val sourceDirs
         return null
     }
 
-    fun addTypeParameters(answer: List<KTypeParameter>, descriptors: List<TypeParameterDescriptor?>): Unit {
+    fun addTypeParameters(answer: MutableList<KTypeParameter>, descriptors: List<TypeParameterDescriptor?>): Unit {
         for (typeParam in descriptors) {
             if (typeParam != null) {
                 val p = createTypeParameter(typeParam)
@@ -1045,7 +1045,7 @@ class KPackage(model: KModel, val descriptor: NamespaceDescriptor,
     fun packageProperties() = properties.filter{ it.extensionClass == null && it.isPublic() }
 }
 
-class KType(val jetType: JetType, model: KModel, val klass: KClass?, val arguments: List<KType> = ArrayList<KType>())
+class KType(val jetType: JetType, model: KModel, val klass: KClass?, val arguments: MutableList<KType> = ArrayList<KType>())
 : KNamed(klass?.name ?: jetType.toString().sure(), model, jetType.getConstructor().getDeclarationDescriptor().sure()) {
     {
         if (klass != null) {
@@ -1056,7 +1056,7 @@ class KType(val jetType: JetType, model: KModel, val klass: KClass?, val argumen
                 val argJetType = arg.getType()
                 val t = model.getType(argJetType)
                 if (t != null) {
-                    $arguments.add(t)
+                    arguments.add(t)
                 }
             }
         }
@@ -1077,10 +1077,10 @@ class KClass(
     val simpleName = descriptor.getName().getName()
     var group: String = "Other"
     var annotations: List<KAnnotation> = arrayList<KAnnotation>()
-    var typeParameters: List<KTypeParameter> = arrayList<KTypeParameter>()
+    var typeParameters: MutableList<KTypeParameter> = arrayList<KTypeParameter>()
     var since: String = ""
     var authors: List<String> = arrayList<String>()
-    var baseClasses: List<KType> = arrayList<KType>()
+    var baseClasses: MutableList<KType> = arrayList<KType>()
     var nestedClasses: List<KClass> = arrayList<KClass>()
 
     public override fun compareTo(other: KClass): Int = name.compareTo(other.name)
@@ -1143,7 +1143,7 @@ class KClass(
     fun isInterface() = kind == "interface"
 
     /** Returns all of the base classes and all of their descendants */
-    fun descendants(answer: Set<KClass> = LinkedHashSet<KClass>()): Set<KClass> {
+    fun descendants(answer: MutableSet<KClass> = LinkedHashSet<KClass>()): Set<KClass> {
         for (b in baseClasses) {
             val c = b.klass
             if (c != null) {
@@ -1161,7 +1161,7 @@ class KFunction(val descriptor: CallableDescriptor, val owner: KClassOrPackage,
         var receiverType: KType? = null,
         var extensionClass: KClass? = null,
         var modifiers: List<String> = arrayList<String>(),
-        var typeParameters: List<KTypeParameter> = arrayList<KTypeParameter>(),
+        var typeParameters: MutableList<KTypeParameter> = arrayList<KTypeParameter>(),
         var exceptions: List<KClass> = arrayList<KClass>(),
         var annotations: List<KAnnotation> = arrayList<KAnnotation>()): KAnnotated(owner.model, descriptor), Comparable<KFunction> {
 
diff --git a/libraries/tools/kdoc/src/test/kotlin/test/kotlin/kdoc/KDocTest.kt b/libraries/tools/kdoc/src/test/kotlin/test/kotlin/kdoc/KDocTest.kt
index 7b5cb4b2438..35db9577a63 100644
--- a/libraries/tools/kdoc/src/test/kotlin/test/kotlin/kdoc/KDocTest.kt
+++ b/libraries/tools/kdoc/src/test/kotlin/test/kotlin/kdoc/KDocTest.kt
@@ -37,12 +37,15 @@ class KDocTest {
         val config = args.docConfig
         config.docOutputDir = outDir.toString()!!
         config.title = "Kotlin API"
-        config.ignorePackages.add("org.jetbrains.kotlin")
-        config.ignorePackages.add("java")
-        config.ignorePackages.add("jet")
-        config.ignorePackages.add("junit")
-        config.ignorePackages.add("sun")
-        config.ignorePackages.add("org")
+
+        //todo@svtk KT-2745
+        val ignorePackages = config.ignorePackages as MutableSet<String>
+        ignorePackages.add("org.jetbrains.kotlin")
+        ignorePackages.add("java")
+        ignorePackages.add("jet")
+        ignorePackages.add("junit")
+        ignorePackages.add("sun")
+        ignorePackages.add("org")
 
         val compiler = KDocCompiler()
         val r = compiler.exec(System.out, args)