diff --git a/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java b/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java
index 0498a5dd3542..6f296f0693c9 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java
@@ -708,12 +708,10 @@ public class FileTypeManagerImpl extends FileTypeManagerEx implements Persistent
   @NotNull
   public FileType getFileTypeByFile(@NotNull VirtualFile file, @Nullable byte[] content) {
     FileType fileType = getByFile(file);
-
-    if (fileType == null) {
-      fileType = file instanceof StubVirtualFile ? UnknownFileType.INSTANCE : getOrDetectFromContent(file, content);
+    if ((fileType == null || fileType instanceof PlainTextLikeFileType) && file instanceof StubVirtualFile) {
+      return getOrDetectFromContent(file, content);
     }
-
-    return fileType;
+    return ObjectUtils.notNull(fileType, UnknownFileType.INSTANCE);
   }
 
   @Nullable // null means all conventional detect methods returned UnknownFileType.INSTANCE, have to detect from content