diff --git a/browser_patches/firefox/BUILD_NUMBER b/browser_patches/firefox/BUILD_NUMBER
index b0ad0dfbc1..c977717905 100644
--- a/browser_patches/firefox/BUILD_NUMBER
+++ b/browser_patches/firefox/BUILD_NUMBER
@@ -1,2 +1,2 @@
-1253
-Changed: pavel.feldman@gmail.com Wed 05 May 2021 01:22:39 PM PDT
+1254
+Changed: lushnikov@chromium.org Thu 06 May 2021 11:02:00 AM PDT
diff --git a/browser_patches/firefox/UPSTREAM_CONFIG.sh b/browser_patches/firefox/UPSTREAM_CONFIG.sh
index b562e32157..c94dc6b577 100644
--- a/browser_patches/firefox/UPSTREAM_CONFIG.sh
+++ b/browser_patches/firefox/UPSTREAM_CONFIG.sh
@@ -1,3 +1,3 @@
 REMOTE_URL="https://github.com/mozilla/gecko-dev"
 BASE_BRANCH="beta"
-BASE_REVISION="5c667fafaaf7f15ed9df2b50e6bb26b570b3fee3"
+BASE_REVISION="8596b58aaea60b1bd772f9e4c5e57416eee9ff1d"
diff --git a/browser_patches/firefox/patches/bootstrap.diff b/browser_patches/firefox/patches/bootstrap.diff
index bf3623dfb5..ae145891fc 100644
--- a/browser_patches/firefox/patches/bootstrap.diff
+++ b/browser_patches/firefox/patches/bootstrap.diff
@@ -92,7 +92,7 @@ index 4fa1d742bd5e0c03b1c93b8bf7cca2fcc8cbded1..1af645fdb86c4a803e1a5f0be08c1d09
    DWORD creationFlags = CREATE_SUSPENDED | CREATE_UNICODE_ENVIRONMENT;
  
 diff --git a/browser/installer/allowed-dupes.mn b/browser/installer/allowed-dupes.mn
-index 4442320c7f893aae5b4bde833ea27b08c22e4d00..6662a380e53b05adbbcf2e6286b36576ae53ea31 100644
+index b4b279cf69968e79b8612b5875961511b4aa2e99..45cc1d3200e975b14d74e2b1b245732e55ea89a8 100644
 --- a/browser/installer/allowed-dupes.mn
 +++ b/browser/installer/allowed-dupes.mn
 @@ -65,6 +65,12 @@ browser/defaults/settings/main/example.json