diff --git a/java/java-psi-impl/src/com/intellij/core/JavaCoreEnvironment.java b/java/java-psi-impl/src/com/intellij/core/JavaCoreEnvironment.java
index 42e9c4cb9ca2..c5cf7931a274 100644
--- a/java/java-psi-impl/src/com/intellij/core/JavaCoreEnvironment.java
+++ b/java/java-psi-impl/src/com/intellij/core/JavaCoreEnvironment.java
@@ -70,7 +70,7 @@ public class JavaCoreEnvironment extends CoreEnvironment {
 
     myApplication.registerService(PsiPackageImplementationHelper.class, new CorePsiPackageImplementationHelper());
 
-    myFileManager = new CoreJavaFileManager(myPsiManager, getLocalFileSystem(), myJarFileSystem);
+    myFileManager = createCoreFileManager();
     myProject.registerService(PsiElementFactory.class, new PsiElementFactoryImpl(myPsiManager));
     myProject.registerService(JavaPsiImplementationHelper.class, new CoreJavaPsiImplementationHelper());
     myProject.registerService(PsiResolveHelper.class, new PsiResolveHelperImpl(myPsiManager));
@@ -92,6 +92,10 @@ public class JavaCoreEnvironment extends CoreEnvironment {
     myApplication.registerService(JavaVersionService.class, new JavaVersionService());
   }
 
+  protected CoreJavaFileManager createCoreFileManager() {
+    return new CoreJavaFileManager(myPsiManager, getLocalFileSystem(), myJarFileSystem);
+  }
+
   public void addToClasspath(File path) {
     final VirtualFile root = path.isFile()
                              ? myJarFileSystem.findFileByPath(path + "!/")