--- a/netwerk/base/security-prefs.js
+++ b/netwerk/base/security-prefs.js
@@ -8,17 +8,17 @@ pref("security.tls.version.fallback-limi
 pref("security.tls.insecure_fallback_hosts", "");
 pref("security.tls.unrestricted_rc4_fallback", false);
 
 pref("security.ssl.treat_unsafe_negotiation_as_broken", false);
 pref("security.ssl.require_safe_negotiation",  false);
 pref("security.ssl.enable_ocsp_stapling", true);
 pref("security.ssl.enable_false_start", true);
 pref("security.ssl.false_start.require-npn", false);
-pref("security.ssl.enable_npn", true);
+pref("security.ssl.enable_npn", false);
 pref("security.ssl.enable_alpn", true);
 
 pref("security.ssl3.ecdhe_rsa_aes_128_gcm_sha256", true);
 pref("security.ssl3.ecdhe_ecdsa_aes_128_gcm_sha256", true);
 pref("security.ssl3.ecdhe_ecdsa_chacha20_poly1305_sha256", true);
 pref("security.ssl3.ecdhe_rsa_chacha20_poly1305_sha256", true);
 pref("security.ssl3.ecdhe_ecdsa_aes_256_gcm_sha384", true);
 pref("security.ssl3.ecdhe_rsa_aes_256_gcm_sha384", true);