diff --git a/step.spec b/step.spec
index f0869e1..1691b7d 100644
--- a/step.spec
+++ b/step.spec
@@ -1,5 +1,5 @@
 Name:          step
-Version:       17.08.3
+Version:       17.12.0
 Release:       1mamba
 Summary:       Interactive Physical Simulator
 Group:         Graphical Desktop/Applications/Educational
@@ -140,6 +140,9 @@ exit 0
 #ChangeLog README TODO
 
 %changelog
+* Sat Dec 23 2017 Automatic Build System <autodist@mambasoft.it> 17.12.0-1mamba
+- automatic version update by autodist
+
 * Fri Nov 10 2017 Automatic Build System <autodist@mambasoft.it> 17.08.3-1mamba
 - automatic version update by autodist