--- a/testing/geckodriver/src/prefs.rs
+++ b/testing/geckodriver/src/prefs.rs
@@ -1,12 +1,12 @@
 use mozprofile::preferences::Pref;
 
 lazy_static! {
-    pub static ref DEFAULT: [(&'static str, Pref); 78] = [
+    pub static ref DEFAULT: [(&'static str, Pref); 79] = [
         // Disable automatic downloading of new releases
         ("app.update.auto", Pref::new(false)),
 
         // Disable automatically upgrading Firefox
         ("app.update.enabled", Pref::new(false)),
 
         // Increase the APZ content response timeout in tests to 1
         // minute.  This is to accommodate the fact that test environments
@@ -171,16 +171,19 @@ lazy_static! {
         ("hangmonitor.timeout", Pref::new(0)),
 
         // Show chrome errors and warnings in the error console
         ("javascript.options.showInConsole", Pref::new(true)),
 
         // Make sure the disk cache does not get auto disabled
         ("network.http.bypass-cachelock-threshold", Pref::new(200000)),
 
+        // Do not prompt with long usernames or passwords in URLs
+        ("network.http.phishy-userpass-length", Pref::new(255)),
+
         // Do not prompt for temporary redirects
         ("network.http.prompt-temp-redirect", Pref::new(false)),
 
         // Disable speculative connections so they are not reported as
         // leaking when they are hanging around
         ("network.http.speculative-parallel-limit", Pref::new(0)),
 
         // Do not automatically switch between offline and online