diff --git a/platform/lang-impl/src/com/intellij/openapi/roots/impl/ContentEntryImpl.java b/platform/lang-impl/src/com/intellij/openapi/roots/impl/ContentEntryImpl.java
index 37acf19b2b8f..af1b82766290 100644
--- a/platform/lang-impl/src/com/intellij/openapi/roots/impl/ContentEntryImpl.java
+++ b/platform/lang-impl/src/com/intellij/openapi/roots/impl/ContentEntryImpl.java
@@ -47,7 +47,7 @@ public class ContentEntryImpl extends RootModelComponentBase implements ContentE
   private final TreeSet<ExcludedOutputFolder> myExcludedOutputFolders = new TreeSet<ExcludedOutputFolder>(ContentFolderComparator.INSTANCE);
   @NonNls public static final String URL_ATTRIBUTE = "url";
 
-  ContentEntryImpl(VirtualFile file, RootModelImpl m) {
+  ContentEntryImpl(@NotNull VirtualFile file, RootModelImpl m) {
     this(file.getUrl(), m);
   }
 
diff --git a/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootModelImpl.java b/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootModelImpl.java
index 18d55ed10e81..74b5c1eae58b 100644
--- a/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootModelImpl.java
+++ b/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootModelImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2012 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.
@@ -534,7 +534,7 @@ public class RootModelImpl implements ModifiableRootModel {
   }
 
   @NotNull
-  public ContentEntry addContentEntry(VirtualFile file) {
+  public ContentEntry addContentEntry(@NotNull VirtualFile file) {
     return addContentEntry(new ContentEntryImpl(file, this));
   }