diff --git a/sysctl.d/50-default.conf b/sysctl.d/50-default.conf
index e263cf0628..b67ae87ca6 100644
--- a/sysctl.d/50-default.conf
+++ b/sysctl.d/50-default.conf
@@ -33,6 +33,9 @@ net.ipv4.conf.all.promote_secondaries = 1
 # Fair Queue CoDel packet scheduler to fight bufferbloat
 net.core.default_qdisc = fq_codel
 
+# Request Explicit Congestion Notification (ECN) on both in and outgoing connections
+net.ipv4.tcp_ecn = 1
+
 # Enable hard and soft link protection
 fs.protected_hardlinks = 1
 fs.protected_symlinks = 1