diff --git a/compiler/tests/org/jetbrains/jet/cli/jvm/compiler/ReadJavaBinaryClassTest.java b/compiler/tests/org/jetbrains/jet/cli/jvm/compiler/ReadJavaBinaryClassTest.java
index 7e76f3be6dd..61cb40bc81c 100644
--- a/compiler/tests/org/jetbrains/jet/cli/jvm/compiler/ReadJavaBinaryClassTest.java
+++ b/compiler/tests/org/jetbrains/jet/cli/jvm/compiler/ReadJavaBinaryClassTest.java
@@ -75,6 +75,7 @@ public class ReadJavaBinaryClassTest extends TestCaseWithTmpdir {
         NamespaceComparator.compareNamespaces(nsa, nsb, false, txtFile);
     }
 
+    @NotNull
     private NamespaceDescriptor compileKotlin() throws Exception {
         JetCoreEnvironment jetCoreEnvironment = JetTestUtils.createEnvironmentWithMockJdk(myTestRootDisposable, CompilerSpecialMode.JDK_HEADERS);