diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -412,9 +412,11 @@
     return;
   }
 
-  // Get the current file lexer we're looking at.  Ignore _Pragma 'files' etc.
-  // Mark the file as a once-only file now.
-  HeaderInfo.MarkFileIncludeOnce(getCurrentFileLexer()->getFileEntry());
+  if (getCurrentFileLexer()->getFileEntry()) {
+    // Get the current file lexer we're looking at.  Ignore _Pragma 'files' etc.
+    // Mark the file as a once-only file now.
+    HeaderInfo.MarkFileIncludeOnce(getCurrentFileLexer()->getFileEntry());
+  }
 }
 
 void Preprocessor::HandlePragmaMark(Token &MarkTok) {