diff --git a/xml/relaxng/test/org/intellij/plugins/relaxNG/HighlightingTestBase.java b/xml/relaxng/test/org/intellij/plugins/relaxNG/HighlightingTestBase.java
index 2b6f0b36e71e..bc8f0511be55 100644
--- a/xml/relaxng/test/org/intellij/plugins/relaxNG/HighlightingTestBase.java
+++ b/xml/relaxng/test/org/intellij/plugins/relaxNG/HighlightingTestBase.java
@@ -139,6 +139,8 @@ public abstract class HighlightingTestBase extends UsefulTestCase implements Ide
   @Override
   protected void tearDown() throws Exception {
     myTestFixture.tearDown();
+    myTestFixture = null;
+
     super.tearDown();
   }