diff --git a/llvm/lib/Fuzzer/FuzzerIO.cpp b/llvm/lib/Fuzzer/FuzzerIO.cpp
index 171b188..0e0c4e9 100644
--- a/llvm/lib/Fuzzer/FuzzerIO.cpp
+++ b/llvm/lib/Fuzzer/FuzzerIO.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 // IO functions.
 //===----------------------------------------------------------------------===//
+#include "FuzzerExtFunctions.h"
 #include "FuzzerInternal.h"
 #include <iterator>
 #include <fstream>
@@ -18,10 +19,6 @@
 #include <cstdarg>
 #include <cstdio>
 
-extern "C" {
-__attribute__((weak)) void __sanitizer_set_report_fd(void *);
-}
-
 namespace fuzzer {
 
 static FILE *OutputFile = stderr;
@@ -126,8 +123,8 @@
     FILE *NewOutputFile = fdopen(OutputFd, "w");
     if (NewOutputFile) {
       OutputFile = NewOutputFile;
-      if (__sanitizer_set_report_fd)
-        __sanitizer_set_report_fd(reinterpret_cast<void*>(OutputFd));
+      if (EF->__sanitizer_set_report_fd)
+        EF->__sanitizer_set_report_fd(reinterpret_cast<void *>(OutputFd));
       close(2);
     }
   }