diff --git a/platform/dvcs-api/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolder.java b/platform/dvcs-api/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolder.java
index bd3d0bcf71d0..3b6b7306cb67 100644
--- a/platform/dvcs-api/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolder.java
+++ b/platform/dvcs-api/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolder.java
@@ -7,7 +7,6 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.Collection;
-import java.util.List;
 import java.util.Set;
 
 public interface VcsRepositoryIgnoredFilesHolder extends Disposable {
@@ -29,7 +28,7 @@ public interface VcsRepositoryIgnoredFilesHolder extends Disposable {
   boolean containsFile(@NotNull FilePath file);
 
   @NotNull
-  List<FilePath> removeIgnoredFiles(@NotNull Collection<? extends FilePath> files);
+  Collection<FilePath> removeIgnoredFiles(@NotNull Collection<? extends FilePath> files);
 
   @NotNull
   Set<FilePath> getIgnoredFilePaths();
diff --git a/platform/dvcs-impl/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolderBase.kt b/platform/dvcs-impl/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolderBase.kt
index 34f3c8082411..012911b28695 100644
--- a/platform/dvcs-impl/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolderBase.kt
+++ b/platform/dvcs-impl/src/com/intellij/dvcs/ignore/VcsRepositoryIgnoredFilesHolderBase.kt
@@ -139,8 +139,8 @@ abstract class VcsRepositoryIgnoredFilesHolderBase<REPOSITORY : Repository>(
     }
   }
 
-  override fun removeIgnoredFiles(filePaths: Collection<FilePath>): List<FilePath> {
-    val removedIgnoredFilePaths = arrayListOf<FilePath>()
+  override fun removeIgnoredFiles(filePaths: Collection<FilePath>): Collection<FilePath> {
+    val removedIgnoredFilePaths = hashSetOf<FilePath>()
     val filePathsSet = filePaths.toHashSet()
     val ignored = SET_LOCK.read { ignoredSet.toHashSet() }
 
diff --git a/plugins/hg4idea/src/org/zmlx/hg4idea/HgVFSListener.java b/plugins/hg4idea/src/org/zmlx/hg4idea/HgVFSListener.java
index 4e3cbdbd668d..2e94859161c0 100644
--- a/plugins/hg4idea/src/org/zmlx/hg4idea/HgVFSListener.java
+++ b/plugins/hg4idea/src/org/zmlx/hg4idea/HgVFSListener.java
@@ -278,7 +278,7 @@ public class HgVFSListener extends VcsVFSListener {
     Map<VirtualFile, Collection<FilePath>> groupFilePathsByHgRoots = HgUtil.groupFilePathsByHgRoots(myProject, filePaths);
     return groupFilePathsByHgRoots.entrySet().stream()
       .map(entry -> getIgnoreRepoHolder(entry.getKey()).removeIgnoredFiles(entry.getValue()))
-      .flatMap(List::stream).collect(Collectors.toList());
+      .flatMap(Collection::stream).collect(Collectors.toList());
   }
 
   /**