diff --git a/xml/dom-openapi/src/com/intellij/util/xml/AbstractConvertContext.java b/xml/dom-openapi/src/com/intellij/util/xml/AbstractConvertContext.java
index b3580d6de9ea..f8f8e69853fd 100644
--- a/xml/dom-openapi/src/com/intellij/util/xml/AbstractConvertContext.java
+++ b/xml/dom-openapi/src/com/intellij/util/xml/AbstractConvertContext.java
@@ -80,7 +80,7 @@ public abstract class AbstractConvertContext extends ConvertContext {
             scope = module.getModuleRuntimeScope(tests);
           }
           else {
-            scope.union(module.getModuleRuntimeScope(tests));
+            scope = scope.union(module.getModuleRuntimeScope(tests));
           }
         }
       }