diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DeclarationScopeProvider.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DeclarationScopeProvider.java
new file mode 100644
index 00000000000..9f4c8fe3f36
--- /dev/null
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DeclarationScopeProvider.java
@@ -0,0 +1,30 @@
+/*
+* Copyright 2010-2015 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 org.jetbrains.kotlin.resolve.lazy;
+
+import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowInfo;
+import org.jetbrains.kotlin.resolve.scopes.JetScope;
+
+public interface DeclarationScopeProvider {
+    @NotNull
+    JetScope getResolutionScopeForDeclaration(@NotNull PsiElement elementOfDeclaration);
+
+    @NotNull
+    DataFlowInfo getOuterDataFlowInfoForDeclaration(@NotNull PsiElement elementOfDeclaration);
+}
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DeclarationScopeProvider.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DeclarationScopeProvider.kt
deleted file mode 100644
index 41574370f82..00000000000
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DeclarationScopeProvider.kt
+++ /dev/null
@@ -1,26 +0,0 @@
-/*
- * Copyright 2010-2015 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 org.jetbrains.kotlin.resolve.lazy
-
-import com.intellij.psi.PsiElement
-import org.jetbrains.kotlin.resolve.scopes.JetScope
-import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowInfo
-
-public trait DeclarationScopeProvider {
-    fun getResolutionScopeForDeclaration(elementOfDeclaration: PsiElement): JetScope
-    fun getOuterDataFlowInfoForDeclaration(elementOfDeclaration: PsiElement): DataFlowInfo
-}