--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1669,17 +1669,17 @@ pref("network.http.spdy.default-hpack-bu
 // the origin host without using a proxy.
 pref("network.http.altsvc.enabled", true);
 pref("network.http.altsvc.oe", true);
 
 // Turn on 0RTT data for TLS 1.3
 pref("security.tls.enable_0rtt_data", true);
 
 // the origin extension impacts h2 coalescing
-pref("network.http.originextension", true);
+pref("network.http.originextension", false);
 
 pref("network.http.diagnostics", false);
 
 pref("network.http.pacing.requests.enabled", true);
 pref("network.http.pacing.requests.min-parallelism", 6);
 pref("network.http.pacing.requests.hz", 80);
 pref("network.http.pacing.requests.burst", 10);