diff --git a/core/descriptors/src/org/jetbrains/jet/renderer/DescriptorRendererImpl.java b/core/descriptors/src/org/jetbrains/jet/renderer/DescriptorRendererImpl.java
index 3c19831b9c6..a9f71d7a446 100644
--- a/core/descriptors/src/org/jetbrains/jet/renderer/DescriptorRendererImpl.java
+++ b/core/descriptors/src/org/jetbrains/jet/renderer/DescriptorRendererImpl.java
@@ -301,6 +301,10 @@ public class DescriptorRendererImpl implements DescriptorRenderer {
             }
             return "???";
         }
+        if (type instanceof FlexibleType && debugMode) {
+            FlexibleType flexibleType = (FlexibleType) type;
+            return "(" + renderType(flexibleType.getLowerBound()) + ".." + renderType(flexibleType.getUpperBound()) + ")";
+        }
         if (type instanceof LazyType && debugMode) {
             return type.toString();
         }