diff --git a/platform/core-impl/src/com/intellij/psi/SingleRootFileViewProvider.java b/platform/core-impl/src/com/intellij/psi/SingleRootFileViewProvider.java
index fcf4d50b5813..4e1c381f498e 100644
--- a/platform/core-impl/src/com/intellij/psi/SingleRootFileViewProvider.java
+++ b/platform/core-impl/src/com/intellij/psi/SingleRootFileViewProvider.java
@@ -41,6 +41,7 @@ import com.intellij.psi.impl.PsiManagerEx;
 import com.intellij.psi.impl.PsiManagerImpl;
 import com.intellij.psi.impl.file.PsiBinaryFileImpl;
 import com.intellij.psi.impl.file.PsiLargeFileImpl;
+import com.intellij.psi.impl.file.impl.FileManager;
 import com.intellij.psi.impl.source.PsiFileImpl;
 import com.intellij.psi.impl.source.PsiPlainTextFileImpl;
 import com.intellij.psi.impl.source.tree.FileElement;
@@ -134,7 +135,11 @@ public class SingleRootFileViewProvider extends UserDataHolderBase implements Fi
   @Nullable
   public final PsiFile getPsi(@NotNull Language target) {
     if (!isPhysical()) {
-      ((PsiManagerEx)myManager).getFileManager().setViewProvider(getVirtualFile(), this);
+      FileManager fileManager = ((PsiManagerEx)myManager).getFileManager();
+      VirtualFile virtualFile = getVirtualFile();
+      if (fileManager.findCachedViewProvider(virtualFile) == null) {
+        fileManager.setViewProvider(virtualFile, this);
+      }
     }
     return getPsiInner(target);
   }
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
index cb36c54839b0..cac35f6cea31 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
@@ -174,7 +174,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
     FileViewProvider provider = getViewProvider();
     final VirtualFile vFile = provider.getVirtualFile();
     if (!vFile.isValid()) return false;
-    if (!provider.isPhysical()) return true; // "dummy" file
+    if (!provider.isEventSystemEnabled()) return true; // "dummy" file
     if (myManager.getProject().isDisposed()) return false;
     return isPsiUpToDate(vFile);
   }
@@ -182,7 +182,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
   protected boolean isPsiUpToDate(@NotNull VirtualFile vFile) {
     final FileViewProvider provider = myManager.findViewProvider(vFile);
     Language language = getLanguage();
-    if (provider.getPsi(language) == this) {
+    if (provider == null || provider.getPsi(language) == this) { // provider == null in tests
       return true;
     }
     Language baseLanguage = provider.getBaseLanguage();