diff --git a/test/core/surface/BUILD b/test/core/surface/BUILD
index 3d2c51e887b..ad36d1c40a6 100644
--- a/test/core/surface/BUILD
+++ b/test/core/surface/BUILD
@@ -135,6 +135,7 @@ grpc_cc_test(
 grpc_cc_test(
     name = "sequential_connectivity_test",
     srcs = ["sequential_connectivity_test.cc"],
+    flaky = True,  # TODO(b/151696318)
     language = "C++",
     deps = [
         "//:gpr",
diff --git a/test/cpp/microbenchmarks/BUILD b/test/cpp/microbenchmarks/BUILD
index 33cca7728af..7e8d371fc3c 100644
--- a/test/cpp/microbenchmarks/BUILD
+++ b/test/cpp/microbenchmarks/BUILD
@@ -283,6 +283,7 @@ grpc_cc_test(
 grpc_cc_test(
     name = "bm_opencensus_plugin",
     srcs = ["bm_opencensus_plugin.cc"],
+    flaky = True,  # TODO(b/151696309)
     language = "C++",
     deps = [
         ":helpers_secure",