diff --git a/pkgs/applications/networking/mailreaders/thunderbird-bin/default.nix b/pkgs/applications/networking/mailreaders/thunderbird-bin/default.nix
index a2be79f5589f..6d9f62e75ab3 100644
--- a/pkgs/applications/networking/mailreaders/thunderbird-bin/default.nix
+++ b/pkgs/applications/networking/mailreaders/thunderbird-bin/default.nix
@@ -1,3 +1,8 @@
+# Update instructions:
+#
+# To update `thunderbird-bin`'s `release_sources.nix`, run from the nixpkgs root:
+#
+#     nix-shell maintainers/scripts/update.nix --argstr package pkgs.firefox-bin-unwrapped
 { stdenv, lib, fetchurl, config, makeWrapper
 , alsa-lib
 , at-spi2-atk
diff --git a/pkgs/applications/networking/mailreaders/thunderbird/packages.nix b/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
index 314d2141de7e..0be69104a5fe 100644
--- a/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
+++ b/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
@@ -44,12 +44,12 @@ rec {
 
   thunderbird-78 = common rec {
     pname = "thunderbird";
-    version = "78.13.0";
+    version = "78.14.0";
     application = "comm/mail";
     binaryName = pname;
     src = fetchurl {
       url = "mirror://mozilla/thunderbird/releases/${version}/source/thunderbird-${version}.source.tar.xz";
-      sha512 = "daee9ea9e57bdfce231a35029807f279a06f8790d71efc8998c78eb42d99a93cf98623170947df99202da038f949ba9111a7ff7adbd43c161794deb6791370a0";
+      sha512 = "0zan30jvv45pd6i59l2kfyfjwivqk5qq6vyf77xhss2dk8qhk3mfrfxpfbkrab676l14b9hs09nr6ni1h1iwn82zx5k7fx5x8sh5dx6";
     };
     patches = [
       ./no-buildconfig-78.patch