diff --git a/llvm/include/llvm/Support/Error.h b/llvm/include/llvm/Support/Error.h
--- a/llvm/include/llvm/Support/Error.h
+++ b/llvm/include/llvm/Support/Error.h
@@ -1281,7 +1281,7 @@
     return OS.str();
   }
 
-  StringRef getFileName() { return FileName; }
+  StringRef getFileName() const { return FileName; }
 
   Error takeError() { return Error(std::move(Err)); }