diff --git a/proxy_chain_manager/browser_profile.py b/proxy_chain_manager/browser_profile.py
index fc99bc9..9089870 100644
--- a/proxy_chain_manager/browser_profile.py
+++ b/proxy_chain_manager/browser_profile.py
@@ -57,14 +57,17 @@ def build_user_js(
         lines.extend(
             [
                 'user_pref("network.proxy.type", 1);',
+                'user_pref("network.proxy.share_proxy_settings", true);',
                 f'user_pref("network.proxy.http", "{proxy_host}");',
                 f'user_pref("network.proxy.http_port", {int(proxy_port)});',
                 f'user_pref("network.proxy.ssl", "{proxy_host}");',
                 f'user_pref("network.proxy.ssl_port", {int(proxy_port)});',
-                f'user_pref("network.proxy.socks", "{proxy_host}");',
-                f'user_pref("network.proxy.socks_port", {int(proxy_port)});',
+                'user_pref("network.proxy.ftp", "");',
+                'user_pref("network.proxy.ftp_port", 0);',
+                'user_pref("network.proxy.socks", "");',
+                'user_pref("network.proxy.socks_port", 0);',
                 'user_pref("network.proxy.socks_version", 5);',
-                'user_pref("network.proxy.socks_remote_dns", true);',
+                'user_pref("network.proxy.socks_remote_dns", false);',
                 'user_pref("network.proxy.no_proxies_on", "");',
             ]
         )
@@ -114,13 +117,6 @@ def build_user_js(
     return "\n".join(lines)
 
 
-def build_prefs_js_marker() -> str:
-    return (
-        "// Proxy God managed profile\n"
-        '// Do not edit manually; user.js is rewritten on launch.\n'
-    )
-
-
 def ensure_firefox_profile(
     profile_dir: Path,
     proxy_host: str,
@@ -132,4 +128,3 @@ def ensure_firefox_profile(
         build_user_js(proxy_host, proxy_port, hard),
         encoding="utf-8",
     )
-    (profile_dir / "prefs.js").write_text(build_prefs_js_marker(), encoding="utf-8")