diff --git a/compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/TypeDeserializer.java b/compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/TypeDeserializer.java
index d46ddfd9fcc..2ded0c5263b 100644
--- a/compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/TypeDeserializer.java
+++ b/compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/TypeDeserializer.java
@@ -25,6 +25,7 @@ import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.types.*;
+import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -120,6 +121,24 @@ public class TypeDeserializer {
             public String toString() {
                 return TypeUtils.toString(this);
             }
+
+            @Override
+            public boolean equals(Object o) {
+                if (this == o) return true;
+                if (!(o instanceof JetType)) return false;
+
+                JetType type = (JetType) o;
+
+                return isNullable() == type.isNullable() && JetTypeChecker.INSTANCE.equalTypes(this, type);
+            }
+
+            @Override
+            public int hashCode() {
+                int result = constructor != null ? constructor.hashCode() : 0;
+                result = 31 * result + arguments.hashCode();
+                result = 31 * result + (isNullable() ? 1 : 0);
+                return result;
+            }
         };
     }