diff --git a/java/java-impl/src/com/intellij/codeInsight/hints/JavaInlayParameterHintsProvider.kt b/java/java-impl/src/com/intellij/codeInsight/hints/JavaInlayParameterHintsProvider.kt
index 95474f8bc583..4173de7f7283 100644
--- a/java/java-impl/src/com/intellij/codeInsight/hints/JavaInlayParameterHintsProvider.kt
+++ b/java/java-impl/src/com/intellij/codeInsight/hints/JavaInlayParameterHintsProvider.kt
@@ -53,7 +53,9 @@ class JavaInlayParameterHintsProvider : InlayParameterHintsProvider {
     return MethodInfo(fullMethodName, paramNames)
   }
 
-  override val defaultBlackList = setOf(
+  override fun getDefaultBlackList() = defaultBlackList
+
+  private val defaultBlackList = setOf(
       "(begin*, end*)",
       "(start*, end*)",
       "(first*, last*)",
diff --git a/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.java b/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.java
new file mode 100644
index 000000000000..cadcc5abeacd
--- /dev/null
+++ b/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2000-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.codeInsight.hints;
+
+import com.intellij.lang.Language;
+import com.intellij.psi.PsiElement;
+import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.Set;
+
+@ApiStatus.Experimental
+public interface InlayParameterHintsProvider {
+
+  /**
+   * Hints for params to be shown
+   */
+  @NotNull
+  List<InlayInfo> getParameterHints(PsiElement element);
+
+  /**
+   * Provides hint info, for alt-enter action (can be MethodInfo or OptionInfo)
+   *
+   * MethodInfo: provides fully qualified method name (e.g. "java.util.Map.put") and list of it's parameter names.
+   * Used to match method with blacklist, and to add method into blacklist
+   * 
+   * OptionInfo: provides option to disable/enable by alt-enter
+   */
+  @Nullable
+  HintInfo getHintInfo(PsiElement element);
+  
+  /**
+   * Default list of patterns for which hints should not be shown
+   */
+  @NotNull
+  Set<String> getDefaultBlackList();
+
+  /**
+   * Returns language which blacklist will be appended to the resulting one
+   * E.g. to prevent possible Groovy and Kotlin extensions from showing hints for blacklisted java methods. 
+   */
+  @Nullable
+  default Language getBlackListDependencyLanguage() {
+    return null;
+  }
+
+  /**
+   * List of supported options, shown in settings dialog
+   */
+  @NotNull
+  default List<Option> getSupportedOptions() {
+    return ContainerUtil.emptyList();
+  }
+
+  /**
+   * If false no blacklist panel will be shown in "Parameter Name Hints Settings"
+   */
+  default boolean isBlackListSupported() {
+    return true;
+  }
+
+}
diff --git a/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.kt b/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.kt
index 5ea964be37f3..82699590d861 100644
--- a/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.kt
+++ b/platform/lang-api/src/com/intellij/codeInsight/hints/InlayParameterHintsProvider.kt
@@ -16,54 +16,11 @@
 package com.intellij.codeInsight.hints
 
 import com.intellij.codeInsight.hints.settings.ParameterNameHintsSettings
-import com.intellij.lang.Language
 import com.intellij.lang.LanguageExtension
-import com.intellij.psi.PsiElement
-import org.jetbrains.annotations.ApiStatus
+
 
 object InlayParameterHintsExtension: LanguageExtension<InlayParameterHintsProvider>("com.intellij.codeInsight.parameterNameHints")
 
-@ApiStatus.Experimental
-interface InlayParameterHintsProvider {
-
-  /**
-   * Hints for params to be shown
-   */
-  fun getParameterHints(element: PsiElement): List<InlayInfo>
-
-  /**
-   * Provides hint info, for alt-enter action (can be MethodInfo or OptionInfo)
-   *
-   * MethodInfo: provides fully qualified method name (e.g. "java.util.Map.put") and list of it's parameter names.
-   * Used to match method with blacklist, and to add method into blacklist
-   * 
-   * OptionInfo: provides option to disable/enable by alt-enter
-   */
-  fun getHintInfo(element: PsiElement): HintInfo?
-  
-  /**
-   * Default list of patterns for which hints should not be shown
-   */
-  val defaultBlackList: Set<String>
-
-  /**
-   * Returns language which blacklist will be appended to the resulting one
-   * E.g. to prevent possible Groovy and Kotlin extensions from showing hints for blacklisted java methods. 
-   */
-  fun getBlackListDependencyLanguage(): Language? = null
-
-  /**
-   * List of supported options, shown in settings dialog
-   */
-  fun getSupportedOptions(): List<Option> = emptyList()
-
-  /**
-   * If false no blacklist panel will be shown in "Parameter Name Hints Settings"
-   */
-  fun isBlackListSupported() = true
-
-}
-
 
 data class InlayInfo(val text: String, val offset: Int)
 
diff --git a/platform/lang-impl/testSources/com/intellij/codeInsight/hints/settings/ParameterNameSettingsTest.kt b/platform/lang-impl/testSources/com/intellij/codeInsight/hints/settings/ParameterNameSettingsTest.kt
index 1d5c265c0c28..4c81c2059fc7 100644
--- a/platform/lang-impl/testSources/com/intellij/codeInsight/hints/settings/ParameterNameSettingsTest.kt
+++ b/platform/lang-impl/testSources/com/intellij/codeInsight/hints/settings/ParameterNameSettingsTest.kt
@@ -23,12 +23,10 @@ import junit.framework.TestCase
 import org.jdom.Element
 
 
-class MockInlayProvider(override val defaultBlackList: Set<String>): InlayParameterHintsProvider {
-
+class MockInlayProvider(private val defaultBlackList: Set<String>): InlayParameterHintsProvider {
   override fun getParameterHints(element: PsiElement) = emptyList<InlayInfo>()
-
   override fun getHintInfo(element: PsiElement) = null
-  
+  override fun getDefaultBlackList() = defaultBlackList
 }
 
 
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/codeInsight/hint/GroovyInlayParameterHintsProvider.kt b/plugins/groovy/src/org/jetbrains/plugins/groovy/codeInsight/hint/GroovyInlayParameterHintsProvider.kt
index 1c4619b25561..6fcb11ef7203 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/codeInsight/hint/GroovyInlayParameterHintsProvider.kt
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/codeInsight/hint/GroovyInlayParameterHintsProvider.kt
@@ -87,7 +87,7 @@ class GroovyInlayParameterHintsProvider : InlayParameterHintsProvider {
     return MethodInfo(fullMethodName, paramNames)
   }
 
-  override val defaultBlackList: Set<String> get() = blackList
+  override fun getDefaultBlackList(): Set<String> = blackList
 
   override fun getBlackListDependencyLanguage() = JavaLanguage.INSTANCE
 }
\ No newline at end of file