diff --git a/tools/valgrind-webrtc/gtest_exclude/peerconnection_unittests.gtest-drmemory_win32.txt b/tools/valgrind-webrtc/gtest_exclude/peerconnection_unittests.gtest-drmemory_win32.txt
index d041dbd526..d9195d0c8d 100644
--- a/tools/valgrind-webrtc/gtest_exclude/peerconnection_unittests.gtest-drmemory_win32.txt
+++ b/tools/valgrind-webrtc/gtest_exclude/peerconnection_unittests.gtest-drmemory_win32.txt
@@ -6,3 +6,6 @@ PeerConnectionEndToEndTest.*
 PeerConnectionInterfaceTest.*
 # Issue 3453
 WebRtcSessionTest.TestReceiveSdesOfferCreateSdesAnswer
+# Flakily fails or crashes on Dr Memory Light.
+# Issue 5978
+WebRtcSessionTest.TestPacketOptionsAndOnPacketSent