diff --git a/thunderbird.spec b/thunderbird.spec
index 7a8a2b0..36acea1 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -9,7 +9,7 @@
 #%define        source_dir                  comm-esr%(echo %version | cut -d. -f1)
 
 Name:          thunderbird
-Version:       91.3.2
+Version:       91.4.0
 Release:       1mamba
 Summary:       Mozilla Thunderbird email, RSS, and newsgroup client
 Group:         Graphical Desktop/Applications/Internet
@@ -444,6 +444,9 @@ fi
 %{tbdir}/removed-files
 
 %changelog
+* Wed Dec 08 2021 Automatic Build System <autodist@mambasoft.it> 91.4.0-1mamba
+- automatic version update by autodist
+
 * Sun Nov 28 2021 Automatic Build System <autodist@mambasoft.it> 91.3.2-1mamba
 - automatic version update by autodist