--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -5649,19 +5649,19 @@ pref("security.mixed_content.use_hsts", 
 #else
 // Change the order of evaluation so HSTS upgrades happen before
 // mixed-content blocking
 pref("security.mixed_content.send_hsts_priming", true);
 pref("security.mixed_content.use_hsts", true);
 #endif
 // Approximately 1 week default cache for HSTS priming failures, in seconds
 pref("security.mixed_content.hsts_priming_cache_timeout", 604800);
-// Force the channel to timeout in 3 seconds if we have not received
+// Force the channel to timeout in 2 seconds if we have not received
 // expects a time in milliseconds
-pref("security.mixed_content.hsts_priming_request_timeout", 3000);
+pref("security.mixed_content.hsts_priming_request_timeout", 2000);
 
 // TODO: Bug 1324406: Treat 'data:' documents as unique, opaque origins
 // If true, data: URIs will be treated as unique opaque origins, hence will use
 // a NullPrincipal as the security context.
 // Otherwise it will inherit the origin from parent node, this is the legacy
 // behavior of Firefox.
 pref("security.data_uri.unique_opaque_origin", false);
 

--- a/netwerk/protocol/http/HSTSPrimerListener.cpp
+++ b/netwerk/protocol/http/HSTSPrimerListener.cpp
@@ -26,18 +26,19 @@ namespace mozilla {
 namespace net {
 
 using namespace mozilla;
 
 NS_IMPL_ISUPPORTS(HSTSPrimingListener, nsIStreamListener,
                   nsIRequestObserver, nsIInterfaceRequestor,
                   nsITimerCallback)
 
-// default to 3000ms, same as the preference
-uint32_t HSTSPrimingListener::sHSTSPrimingTimeout = 3000;
+// default to 2000ms, same as the preference
+// security.mixed_content.hsts_priming_request_timeout
+uint32_t HSTSPrimingListener::sHSTSPrimingTimeout = 2000;
 
 
 HSTSPrimingListener::HSTSPrimingListener(nsIHstsPrimingCallback* aCallback)
   : mCallback(aCallback)
 {
   static nsresult rv =
     Preferences::AddUintVarCache(&sHSTSPrimingTimeout,
         "security.mixed_content.hsts_priming_request_timeout");

--- a/security/manager/ssl/security-prefs.js
+++ b/security/manager/ssl/security-prefs.js
@@ -132,11 +132,11 @@ pref("security.mixed_content.use_hsts", 
 #else
 // Change the order of evaluation so HSTS upgrades happen before
 // mixed-content blocking
 pref("security.mixed_content.send_hsts_priming", true);
 pref("security.mixed_content.use_hsts", true);
 #endif
 // Approximately 1 week default cache for HSTS priming failures, in seconds
 pref ("security.mixed_content.hsts_priming_cache_timeout", 604800);
-// Force the channel to timeout in 3 seconds if we have not received
+// Force the channel to timeout in 2 seconds if we have not received
 // expects a time in milliseconds
-pref ("security.mixed_content.hsts_priming_request_timeout", 3000);
+pref ("security.mixed_content.hsts_priming_request_timeout", 2000);