diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h
index e0048f51408..e942d0af916 100644
--- a/include/llvm/Support/raw_ostream.h
+++ b/include/llvm/Support/raw_ostream.h
@@ -346,7 +346,7 @@ public:
   /// itself to own the file descriptor. In particular, it will close the
   /// file descriptor when it is done (this is necessary to detect
   /// output errors).
-  raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
+  raw_fd_ostream(StringRef Filename, std::string &ErrorInfo,
                  sys::fs::OpenFlags Flags);
 
   /// raw_fd_ostream ctor - FD is the file descriptor that this writes to.  If
diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index 3c45743666d..154948301b6 100644
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -430,16 +430,15 @@ void format_object_base::home() {
 /// occurs, information about the error is put into ErrorInfo, and the
 /// stream should be immediately destroyed; the string will be empty
 /// if no error occurred.
-raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
+raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::string &ErrorInfo,
                                sys::fs::OpenFlags Flags)
     : Error(false), UseAtomicWrites(false), pos(0) {
-  assert(Filename != 0 && "Filename is null");
   ErrorInfo.clear();
 
   // Handle "-" as stdout. Note that when we do this, we consider ourself
   // the owner of stdout. This means that we can do things like close the
   // file descriptor when we're done and set the "binary" flag globally.
-  if (Filename[0] == '-' && Filename[1] == 0) {
+  if (Filename == "-") {
     FD = STDOUT_FILENO;
     // If user requested binary then put stdout into binary mode if
     // possible.