diff --git a/pkgs/applications/networking/mailreaders/thunderbird/D124361.diff b/pkgs/applications/networking/mailreaders/thunderbird/D124361.diff
deleted file mode 100644
index 42dee06a26bf..000000000000
--- a/pkgs/applications/networking/mailreaders/thunderbird/D124361.diff
+++ /dev/null
@@ -1,22 +0,0 @@
-diff --git a/comm/mail/config/mozconfigs/common b/comm/mail/config/mozconfigs/common
---- a/comm/mail/config/mozconfigs/common
-+++ b/comm/mail/config/mozconfigs/common
-@@ -1,6 +1,3 @@
- ac_add_options --enable-application=comm/mail
- 
--# Disable enforcing that add-ons are signed by the trusted root.
--MOZ_REQUIRE_SIGNING=
--
- . "$topsrcdir/build/mozconfig.common.override"
-diff --git a/comm/mail/moz.configure b/comm/mail/moz.configure
---- a/comm/mail/moz.configure
-+++ b/comm/mail/moz.configure
-@@ -12,6 +12,7 @@
- imply_option("MOZ_CRASHREPORTER_URL", "https://crash-reports.thunderbird.net/")
- 
- imply_option("--enable-default-browser-agent", False)
-+imply_option("MOZ_REQUIRE_SIGNING", False)
- 
- 
- @depends(target_is_windows, target_is_linux)
-
diff --git a/pkgs/applications/networking/mailreaders/thunderbird/no-buildconfig-90.patch b/pkgs/applications/networking/mailreaders/thunderbird/no-buildconfig-90.patch
deleted file mode 100644
index c4e29f6355cf..000000000000
--- a/pkgs/applications/networking/mailreaders/thunderbird/no-buildconfig-90.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-Remove about:buildconfig.  If used as-is, it would add unnecessary runtime dependencies.
---- a/comm/mail/base/jar.mn
-+++ b/comm/mail/base/jar.mn
-@@ -119,9 +119,6 @@ messenger.jar:
- % override chrome://mozapps/content/profile/profileDowngrade.js chrome://messenger/content/profileDowngrade.js
- % override chrome://mozapps/content/profile/profileDowngrade.xhtml chrome://messenger/content/profileDowngrade.xhtml
- 
--*   content/messenger/buildconfig.html              (content/buildconfig.html)
--% override chrome://global/content/buildconfig.html chrome://messenger/content/buildconfig.html
--
- # L10n resources and overrides.
- % override chrome://mozapps/locale/profile/profileDowngrade.dtd chrome://messenger/locale/profileDowngrade.dtd
- % override chrome://global/locale/netError.dtd chrome://messenger/locale/netError.dtd
diff --git a/pkgs/applications/networking/mailreaders/thunderbird/packages.nix b/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
index 0be69104a5fe..1aca35d56b19 100644
--- a/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
+++ b/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
@@ -10,21 +10,14 @@ in
 rec {
   thunderbird = common rec {
     pname = "thunderbird";
-    version = "91.1.0";
+    version = "91.1.1";
     application = "comm/mail";
     binaryName = pname;
     src = fetchurl {
       url = "mirror://mozilla/thunderbird/releases/${version}/source/thunderbird-${version}.source.tar.xz";
-      sha512 = "c465ff25d67c5c28db53d3b1ccda10a743276e58c693406bf31bde0253f34123348180ae18765bd60b958c050e3a874dd69ac82d7612007a8c7a2e25939840ff";
+      sha512 = "2da102f9ec42489fc785ccdabcc7fdbc826f2df5e8e76c65866a44a221e762f59647ea265fe4907c18f0d3f1e04199e809235b4587ea17bdc1155e829f57ff2f";
     };
     patches = [
-      ./no-buildconfig-90.patch
-
-      # There is a bug in Thunderbird 91 where add-ons are required
-      # to be signed when the build is run with default settings.
-      # https://bugzilla.mozilla.org/show_bug.cgi?id=1727113
-      # https://phabricator.services.mozilla.com/D124361
-      ./D124361.diff
     ];
 
     meta = with lib; {