diff --git a/quic/test_tools/simple_session_notifier_test.cc b/quic/test_tools/simple_session_notifier_test.cc
index 058f220..4dc48a7 100644
--- a/quic/test_tools/simple_session_notifier_test.cc
+++ b/quic/test_tools/simple_session_notifier_test.cc
@@ -135,6 +135,8 @@
 
 TEST_F(SimpleSessionNotifierTest, NeuterUnencryptedData) {
   if (QuicVersionUsesCryptoFrames(connection_.transport_version())) {
+    // This test writes crypto data through crypto streams. It won't work when
+    // crypto frames are used instead.
     return;
   }
   InSequence s;
@@ -175,6 +177,8 @@
 
 TEST_F(SimpleSessionNotifierTest, OnCanWrite) {
   if (QuicVersionUsesCryptoFrames(connection_.transport_version())) {
+    // This test writes crypto data through crypto streams. It won't work when
+    // crypto frames are used instead.
     return;
   }
   InSequence s;