diff --git a/platform/platform-impl/src/com/intellij/ide/lightEdit/project/LightEditProjectFileIndex.java b/platform/platform-impl/src/com/intellij/ide/lightEdit/project/LightEditProjectFileIndex.java
index 87034c923ee5..90f61bea5cab 100644
--- a/platform/platform-impl/src/com/intellij/ide/lightEdit/project/LightEditProjectFileIndex.java
+++ b/platform/platform-impl/src/com/intellij/ide/lightEdit/project/LightEditProjectFileIndex.java
@@ -176,4 +176,7 @@ final class LightEditProjectFileIndex implements ProjectFileIndex {
   public @Nullable String getUnloadedModuleNameForFile(@NotNull VirtualFile fileOrDir) {
     return null;
   }
+
+  @Override
+  public @Nullable VirtualFile getWorkspaceContentFileSetRoot(@NotNull VirtualFile fileOrDir) { return null; }
 }
diff --git a/platform/projectModel-api/src/com/intellij/openapi/roots/ProjectFileIndex.java b/platform/projectModel-api/src/com/intellij/openapi/roots/ProjectFileIndex.java
index dc44adb91dfc..5b7f1a2c68c2 100644
--- a/platform/projectModel-api/src/com/intellij/openapi/roots/ProjectFileIndex.java
+++ b/platform/projectModel-api/src/com/intellij/openapi/roots/ProjectFileIndex.java
@@ -4,6 +4,7 @@ package com.intellij.openapi.roots;
 import com.intellij.openapi.fileTypes.FileTypeRegistry;
 import com.intellij.openapi.module.Module;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.IntellijInternalApi;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.platform.workspace.jps.entities.LibraryEntity;
 import com.intellij.platform.workspace.jps.entities.SdkEntity;
@@ -227,4 +228,9 @@ public interface ProjectFileIndex extends FileIndex {
    * to an unloaded module.
    */
   @Nullable String getUnloadedModuleNameForFile(@NotNull VirtualFile fileOrDir);
+
+  /// Use [com.intellij.workspaceModel.core.fileIndex.WorkspaceFileIndex.getContentFileSetRoot] instead
+  @ApiStatus.Internal
+  @IntellijInternalApi
+  @Nullable VirtualFile getWorkspaceContentFileSetRoot(@NotNull VirtualFile fileOrDir);
 }
diff --git a/platform/projectModel-impl/src/com/intellij/openapi/roots/impl/ProjectFileIndexImpl.java b/platform/projectModel-impl/src/com/intellij/openapi/roots/impl/ProjectFileIndexImpl.java
index d8a4d2b42a9d..151942feacde 100644
--- a/platform/projectModel-impl/src/com/intellij/openapi/roots/impl/ProjectFileIndexImpl.java
+++ b/platform/projectModel-impl/src/com/intellij/openapi/roots/impl/ProjectFileIndexImpl.java
@@ -18,6 +18,7 @@ import com.intellij.platform.workspace.jps.entities.SdkEntity;
 import com.intellij.platform.workspace.storage.ImmutableEntityStorage;
 import com.intellij.util.SmartList;
 import com.intellij.util.containers.ContainerUtil;
+import com.intellij.workspaceModel.core.fileIndex.WorkspaceFileIndex;
 import com.intellij.workspaceModel.core.fileIndex.WorkspaceFileKind;
 import com.intellij.workspaceModel.core.fileIndex.WorkspaceFileSet;
 import com.intellij.workspaceModel.core.fileIndex.WorkspaceFileSetWithCustomData;
@@ -317,6 +318,11 @@ public class ProjectFileIndexImpl extends FileIndexBase implements ProjectFileIn
     return fileSet != null ? fileSet.getData().getModuleName() : null;
   }
 
+  @Override
+  public @Nullable VirtualFile getWorkspaceContentFileSetRoot(@NotNull VirtualFile fileOrDir) {
+    return WorkspaceFileIndex.getInstance(myProject).getContentFileSetRoot(fileOrDir, true);
+  }
+
   @Override
   protected boolean isScopeDisposed() {
     return myProject.isDisposed();