Index: lib/Fuzzer/afl/afl_driver.cpp
===================================================================
--- lib/Fuzzer/afl/afl_driver.cpp
+++ lib/Fuzzer/afl/afl_driver.cpp
@@ -120,6 +120,7 @@
                                              "slowest_unit_time_sec  : %u\n";
 
 // Copied from FuzzerUtil.cpp.
+#if LIBFUZZER_POSIX
 size_t GetPeakRSSMb() {
   struct rusage usage;
   if (getrusage(RUSAGE_SELF, &usage))
@@ -134,6 +135,14 @@
   assert(0 && "GetPeakRSSMb() is not implemented for your platform");
   return 0;
 }
+#elif LIBFUZZER_WINDOWS
+size_t GetPeakRSSMb() {
+  PROCESS_MEMORY_COUNTERS info;
+  if (!GetProcessMemoryInfo(GetCurrentProcess(), &info, sizeof(info)))
+    return 0;
+  return info.PeakWorkingSetSize >> 20;
+}
+#endif
 
 // Based on SetSigaction in FuzzerUtil.cpp
 static void SetSigaction(int signum,