Index: lib/Fuzzer/FuzzerIO.h
===================================================================
--- lib/Fuzzer/FuzzerIO.h
+++ lib/Fuzzer/FuzzerIO.h
@@ -69,6 +69,8 @@
 
 void DiscardOutput(int Fd);
 
+void* GetHandleFromFd(int fd);
+
 }  // namespace fuzzer
 
 #endif  // LLVM_FUZZER_IO_H
Index: lib/Fuzzer/FuzzerIO.cpp
===================================================================
--- lib/Fuzzer/FuzzerIO.cpp
+++ lib/Fuzzer/FuzzerIO.cpp
@@ -96,7 +96,7 @@
     if (NewOutputFile) {
       OutputFile = NewOutputFile;
       if (EF->__sanitizer_set_report_fd)
-        EF->__sanitizer_set_report_fd(reinterpret_cast<void *>(OutputFd));
+        EF->__sanitizer_set_report_fd(GetHandleFromFd(OutputFd));
       DiscardOutput(2);
     }
   }
Index: lib/Fuzzer/FuzzerIOPosix.cpp
===================================================================
--- lib/Fuzzer/FuzzerIOPosix.cpp
+++ lib/Fuzzer/FuzzerIOPosix.cpp
@@ -83,6 +83,10 @@
   fclose(Temp);
 }
 
+void* GetHandleFromFd(int fd) {
+  return static_cast<void*>(fd);
+}
+
 std::string DirName(const std::string &FileName) {
   char *Tmp = new char[FileName.size() + 1];
   memcpy(Tmp, FileName.c_str(), FileName.size() + 1);
Index: lib/Fuzzer/FuzzerIOWindows.cpp
===================================================================
--- lib/Fuzzer/FuzzerIOWindows.cpp
+++ lib/Fuzzer/FuzzerIOWindows.cpp
@@ -149,6 +149,10 @@
   fclose(Temp);
 }
 
+void* GetHandleFromFd(int fd) {
+  return reinterpret_cast<void*>(_get_osfhandle(fd));
+}
+
 static bool IsSeparator(char C) {
   return C == '\\' || C == '/';
 }