diff --git a/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/FoldingUpdate.java b/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/FoldingUpdate.java
index 7aa372079d43..bf10e3ed18b0 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/FoldingUpdate.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/FoldingUpdate.java
@@ -24,7 +24,7 @@ import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.registry.Registry;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.DebugUtil;
-import com.intellij.psi.impl.source.tree.injected.FoldingModelWindow;
+import com.intellij.psi.impl.source.tree.injected.FoldingRegionWindow;
 import com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtil;
 import com.intellij.psi.util.CachedValue;
 import com.intellij.psi.util.CachedValueProvider;
@@ -171,7 +171,8 @@ public class FoldingUpdate {
       });
       EditorFoldingInfo info = EditorFoldingInfo.get(editor);
       for (FoldRegion region : editor.getFoldingModel().getAllFoldRegions()) {
-        if (FoldingModelWindow.isOutdatedInjectedRegion(region)) {
+        FoldingRegionWindow injectedRegion = FoldingRegionWindow.getInjectedRegion(region);
+        if (injectedRegion != null && !injectedRegion.isValid()) {
           info.removeRegion(region);
         }
       }
diff --git a/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingModelWindow.java b/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingModelWindow.java
index 976b5e804ac5..95b1ff1bfe75 100644
--- a/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingModelWindow.java
+++ b/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingModelWindow.java
@@ -24,8 +24,7 @@ import java.util.List;
 /**
  * @author cdr
  */
-@ApiStatus.Internal
-public class FoldingModelWindow implements FoldingModelEx, ModificationTracker {
+class FoldingModelWindow implements FoldingModelEx, ModificationTracker {
   private final FoldingModelEx myDelegate;
   private final DocumentWindow myDocumentWindow;
   private final EditorWindow myEditorWindow;
@@ -107,11 +106,6 @@ public class FoldingModelWindow implements FoldingModelEx, ModificationTracker {
     return window != null && window.getEditor() == myEditorWindow ? window : null;
   }
 
-  public static boolean isOutdatedInjectedRegion(@NotNull FoldRegion hostRegion) {
-    FoldingRegionWindow window = hostRegion.getUserData(FOLD_REGION_WINDOW);
-    return window != null && !((DocumentWindow)window.getEditor().getDocument()).isValid();
-  }
-
   @Override
   public void runBatchFoldingOperation(@NotNull Runnable operation, boolean allowMovingCaret, boolean keepRelativeCaretPosition) {
     myDelegate.runBatchFoldingOperation(operation, allowMovingCaret, keepRelativeCaretPosition);
@@ -138,7 +132,7 @@ public class FoldingModelWindow implements FoldingModelEx, ModificationTracker {
     return FoldRegion.EMPTY_ARRAY; //todo implement
   }
 
-  private static final Key<FoldingRegionWindow> FOLD_REGION_WINDOW = Key.create("FOLD_REGION_WINDOW");
+  static final Key<FoldingRegionWindow> FOLD_REGION_WINDOW = Key.create("FOLD_REGION_WINDOW");
   @Override
   public FoldRegion createFoldRegion(int startOffset, int endOffset, @NotNull String placeholder, FoldingGroup group, boolean neverExpands) {
     TextRange hostRange = myDocumentWindow.injectedToHost(new TextRange(startOffset, endOffset));
diff --git a/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingRegionWindow.java b/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingRegionWindow.java
index 1525a2b8f6d4..be89cf1d76a4 100644
--- a/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingRegionWindow.java
+++ b/platform/lang-impl/src/com/intellij/psi/impl/source/tree/injected/FoldingRegionWindow.java
@@ -76,4 +76,8 @@ public class FoldingRegionWindow extends RangeMarkerWindow implements FoldRegion
   public void setPlaceholderText(@NotNull String text) {
     myHostRegion.setPlaceholderText(text);
   }
+
+  public static FoldingRegionWindow getInjectedRegion(@NotNull FoldRegion hostRegion) {
+    return hostRegion.getUserData(FoldingModelWindow.FOLD_REGION_WINDOW);
+  }
 }