Index: lib/sanitizer_common/sanitizer_coverage_libcdep.cc
===================================================================
--- lib/sanitizer_common/sanitizer_coverage_libcdep.cc
+++ lib/sanitizer_common/sanitizer_coverage_libcdep.cc
@@ -171,7 +171,14 @@
   //   - not thread-safe;
   //   - does not support long traces;
   //   - not tuned for performance.
+#if SANITIZER_WINDOWS
+  // On windows, large allocations are often failing which is making unittests
+  // flaky. TODO(etienneb): Find a way to support coverage of larger executable
+  // in 64-bits.
+  static const uptr kTrEventArrayMaxSize = 1 << 22;
+#else
   static const uptr kTrEventArrayMaxSize = FIRST_32_SECOND_64(1 << 22, 1 << 30);
+#endif
   u32 *tr_event_array;
   uptr tr_event_array_size;
   u32 *tr_event_pointer;