diff --git a/java/java-psi-api/src/com/intellij/psi/PsiSubstitutor.java b/java/java-psi-api/src/com/intellij/psi/PsiSubstitutor.java
index ddc301e0eabe..0fcc46ea3325 100644
--- a/java/java-psi-api/src/com/intellij/psi/PsiSubstitutor.java
+++ b/java/java-psi-api/src/com/intellij/psi/PsiSubstitutor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2013 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.
@@ -37,7 +37,9 @@ public interface PsiSubstitutor {
    * <b>Example:</b> consider class <code>List&lt;E&gt;</code>. <code>this</code>
    * inside class <code>List</code> has type List with EMPTY substitutor.
    */
+  @NotNull
   PsiSubstitutor EMPTY = EmptySubstitutor.getInstance();
+  @NotNull
   PsiSubstitutor UNKNOWN = EMPTY;
 
   /**
@@ -61,7 +63,7 @@ public interface PsiSubstitutor {
 
   //Should be used with great care, be sure to prevent infinite recursion that could arise
   // from the use of recursively bounded type parameters
-  PsiType substituteWithBoundsPromotion(PsiTypeParameter typeParameter);
+  PsiType substituteWithBoundsPromotion(@NotNull PsiTypeParameter typeParameter);
 
   /**
    * Creates a substitutor instance which provides the specified parameter to type mapping in addition
@@ -71,7 +73,8 @@ public interface PsiSubstitutor {
    * @param mapping        the type to which the parameter is mapped.
    * @return the new substitutor instance.
    */
-  PsiSubstitutor put(PsiTypeParameter classParameter, PsiType mapping);
+  @NotNull
+  PsiSubstitutor put(@NotNull PsiTypeParameter classParameter, PsiType mapping);
 
   /**
    * Creates a substitutor instance which maps the type parameters of the specified class to the
@@ -81,7 +84,8 @@ public interface PsiSubstitutor {
    * @param mappings    the types to which the parameters are mapped.
    * @return the new substitutor instance.
    */
-  PsiSubstitutor putAll(PsiClass parentClass, PsiType[] mappings);
+  @NotNull
+  PsiSubstitutor putAll(@NotNull PsiClass parentClass, PsiType[] mappings);
 
   /**
    * Creates a substitutor instance containing all mappings from this substitutor and the
@@ -90,7 +94,8 @@ public interface PsiSubstitutor {
    * @param another the substitutor to get the mappings from.
    * @return the new substitutor instance.
    */
-  PsiSubstitutor putAll(PsiSubstitutor another);
+  @NotNull
+  PsiSubstitutor putAll(@NotNull PsiSubstitutor another);
 
   /**
    * Returns the map from type parameters to types used for substitution by this substitutor.
diff --git a/java/java-psi-impl/src/com/intellij/psi/impl/EmptySubstitutorImpl.java b/java/java-psi-impl/src/com/intellij/psi/impl/EmptySubstitutorImpl.java
index 9a327a846a04..dc8a2e8eeef8 100644
--- a/java/java-psi-impl/src/com/intellij/psi/impl/EmptySubstitutorImpl.java
+++ b/java/java-psi-impl/src/com/intellij/psi/impl/EmptySubstitutorImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2013 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.
@@ -38,26 +38,29 @@ public final class EmptySubstitutorImpl extends EmptySubstitutor {
   }
 
   @Override
-  public PsiType substituteWithBoundsPromotion(PsiTypeParameter typeParameter) {
+  public PsiType substituteWithBoundsPromotion(@NotNull PsiTypeParameter typeParameter) {
     return JavaPsiFacade.getInstance(typeParameter.getProject()).getElementFactory().createType(typeParameter);
   }
 
+  @NotNull
   @Override
-  public PsiSubstitutor put(PsiTypeParameter classParameter, PsiType mapping){
+  public PsiSubstitutor put(@NotNull PsiTypeParameter classParameter, PsiType mapping){
     if (mapping != null && !mapping.isValid()) {
       LOG.error("Invalid type in substitutor: " + mapping);
     }
     return new PsiSubstitutorImpl(classParameter, mapping);
   }
 
+  @NotNull
   @Override
-  public PsiSubstitutor putAll(PsiClass parentClass, PsiType[] mappings){
+  public PsiSubstitutor putAll(@NotNull PsiClass parentClass, PsiType[] mappings){
     if(!parentClass.hasTypeParameters()) return this;
     return new PsiSubstitutorImpl(parentClass, mappings);
   }
 
+  @NotNull
   @Override
-  public PsiSubstitutor putAll(PsiSubstitutor another) {
+  public PsiSubstitutor putAll(@NotNull PsiSubstitutor another) {
     return another;
   }
 
diff --git a/java/java-psi-impl/src/com/intellij/psi/impl/PsiSubstitutorImpl.java b/java/java-psi-impl/src/com/intellij/psi/impl/PsiSubstitutorImpl.java
index 94f6627ebe4b..1b2dadbecbb6 100644
--- a/java/java-psi-impl/src/com/intellij/psi/impl/PsiSubstitutorImpl.java
+++ b/java/java-psi-impl/src/com/intellij/psi/impl/PsiSubstitutorImpl.java
@@ -86,7 +86,7 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
     return mySubstitutionMap.containsKey(typeParameter);
   }
 
-  private PsiType getFromMap(PsiTypeParameter typeParameter) {
+  private PsiType getFromMap(@NotNull PsiTypeParameter typeParameter) {
     if (typeParameter instanceof LightTypeParameter) {
       typeParameter = ((LightTypeParameter)typeParameter).getDelegate();
     }
@@ -105,7 +105,7 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
   }
 
   @Override
-  public PsiType substituteWithBoundsPromotion(PsiTypeParameter typeParameter) {
+  public PsiType substituteWithBoundsPromotion(@NotNull PsiTypeParameter typeParameter) {
     return addBounds(substitute(typeParameter), typeParameter);
   }
 
@@ -306,7 +306,7 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
       return result;
     }
 
-    private PsiType substituteTypeParameter(final PsiTypeParameter typeParameter) {
+    private PsiType substituteTypeParameter(@NotNull PsiTypeParameter typeParameter) {
       PsiType t = getFromMap(typeParameter);
       if (myKind == SubstituteKind.SIMPLE) {
         return t;
@@ -350,7 +350,7 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
     }
   }
 
-  private PsiType addBounds(PsiType substituted, final PsiTypeParameter typeParameter) {
+  private PsiType addBounds(PsiType substituted, @NotNull PsiTypeParameter typeParameter) {
     PsiType oldSubstituted = substituted;
     PsiElement captureContext = null;
     if (substituted instanceof PsiCapturedWildcardType) {
@@ -432,6 +432,7 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
     return new PsiSubstitutorImpl(mySubstitutionMap);
   }
 
+  @NotNull
   @Override
   public PsiSubstitutor put(@NotNull PsiTypeParameter typeParameter, PsiType mapping) {
     PsiSubstitutorImpl ret = clone();
@@ -461,6 +462,7 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
     }
   }
 
+  @NotNull
   @Override
   public PsiSubstitutor putAll(@NotNull PsiClass parentClass, PsiType[] mappings) {
     PsiSubstitutorImpl substitutor = clone();
@@ -468,8 +470,9 @@ public class PsiSubstitutorImpl implements PsiSubstitutor {
     return substitutor;
   }
 
+  @NotNull
   @Override
-  public PsiSubstitutor putAll(PsiSubstitutor another) {
+  public PsiSubstitutor putAll(@NotNull PsiSubstitutor another) {
     if (another instanceof EmptySubstitutorImpl) return this;
     final PsiSubstitutorImpl anotherImpl = (PsiSubstitutorImpl)another;
     PsiSubstitutorImpl substitutor = clone();