diff --git a/llvm/unittests/Support/TimeValueTest.cpp b/llvm/unittests/Support/TimeValueTest.cpp
index 0fd5675..fb2abe3 100644
--- a/llvm/unittests/Support/TimeValueTest.cpp
+++ b/llvm/unittests/Support/TimeValueTest.cpp
@@ -20,4 +20,20 @@
   EXPECT_TRUE(abs(static_cast<long>(now_t - now.toEpochTime())) < 2);
 }
 
+TEST(TimeValue, Win32FILETIME) {
+  uint64_t epoch_as_filetime = 0x19DB1DED53E8000ULL;
+  uint32_t ns = 765432100;
+  sys::TimeValue epoch;
+
+  // FILETIME has 100ns of intervals.
+  uint64_t ft1970 = epoch_as_filetime + ns / 100;
+  epoch.fromWin32Time(ft1970);
+
+  // The "seconds" part in Posix time may be expected as zero.
+  EXPECT_EQ(ns / 100, epoch.toPosixTime());
+
+  // Confirm it reversible.
+  EXPECT_EQ(ft1970, epoch.toWin32Time());
+}
+
 }