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 64c219cfc58a..8aded5f639e3 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
@@ -1169,7 +1169,9 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
   }
 
   public final boolean useStrongRefs() {
-    return myTrees.useStrongRefs;
+    if (myTrees.useStrongRefs) return true;
+    return myViewProvider instanceof MultiplePsiFilesPerDocumentFileViewProvider &&
+           myViewProvider.getAllFiles().stream().anyMatch(root -> root instanceof PsiFileImpl && ((PsiFileImpl)root).myTrees.useStrongRefs);
   }
 
   public boolean mayCacheAst() {