diff --git a/llvm/lib/Fuzzer/FuzzerUtil.cpp b/llvm/lib/Fuzzer/FuzzerUtil.cpp
index f4c6fa7..f06060b 100644
--- a/llvm/lib/Fuzzer/FuzzerUtil.cpp
+++ b/llvm/lib/Fuzzer/FuzzerUtil.cpp
@@ -246,7 +246,7 @@
 }
 
 void SleepSeconds(int Seconds) {
-  std::this_thread::sleep_for(std::chrono::seconds(Seconds));
+  sleep(Seconds);  // Use C API to avoid coverage from instrumented libc++.
 }
 
 int GetPid() { return getpid(); }