diff --git a/core/descriptors/src/org/jetbrains/jet/lang/descriptors/impl/ClassDescriptorBase.java b/core/descriptors/src/org/jetbrains/jet/lang/descriptors/impl/ClassDescriptorBase.java
index 49782ad64c0..b6daa06956e 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/descriptors/impl/ClassDescriptorBase.java
+++ b/core/descriptors/src/org/jetbrains/jet/lang/descriptors/impl/ClassDescriptorBase.java
@@ -29,7 +29,7 @@ import java.util.Map;
 
 public abstract class ClassDescriptorBase implements ClassDescriptor {
 
-    protected JetType defaultType;
+    protected volatile JetType defaultType;
 
     protected abstract JetScope getScopeForMemberLookup();