diff --git a/absl/synchronization/internal/per_thread_sem_test.cc b/absl/synchronization/internal/per_thread_sem_test.cc
index 2eb8067..e3cf41d 100644
--- a/absl/synchronization/internal/per_thread_sem_test.cc
+++ b/absl/synchronization/internal/per_thread_sem_test.cc
@@ -162,7 +162,7 @@
   absl::Duration slop = absl::Milliseconds(1);
 #ifdef _MSC_VER
   // Use higher slop on MSVC due to flaky test failures.
-  slop = absl::Milliseconds(8);
+  slop = absl::Milliseconds(16);
 #endif
   EXPECT_LE(delay - slop, elapsed)
       << "Wait returned " << delay - elapsed