diff --git a/llvm/lib/Fuzzer/FuzzerUtilDarwin.cpp b/llvm/lib/Fuzzer/FuzzerUtilDarwin.cpp
index 4c90998..62f0f22 100644
--- a/llvm/lib/Fuzzer/FuzzerUtilDarwin.cpp
+++ b/llvm/lib/Fuzzer/FuzzerUtilDarwin.cpp
@@ -10,6 +10,7 @@
 //===----------------------------------------------------------------------===//
 #include "FuzzerDefs.h"
 #if LIBFUZZER_APPLE
+#include "FuzzerIO.h"
 #include <mutex>
 #include <signal.h>
 #include <spawn.h>