diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 5ffe65f..0defe5c 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -599,15 +599,10 @@
 
 void GeneratePTHAction::ExecuteAction() {
   CompilerInstance &CI = getCompilerInstance();
-  llvm::raw_fd_ostream *OS = CI.createDefaultOutputFile(true, getCurrentFile());
+  raw_pwrite_stream *OS = CI.createDefaultOutputFile(true, getCurrentFile());
   if (!OS)
     return;
 
-  if (!OS->supportsSeeking()) {
-    // FIXME: Don't fail this way.
-    llvm::report_fatal_error("PTH requires a seekable file for output!");
-  }
-
   CacheTokens(CI.getPreprocessor(), OS);
 }