diff --git a/filesystem.spec b/filesystem.spec
index 3b133d1..5f03d8d 100644
--- a/filesystem.spec
+++ b/filesystem.spec
@@ -2,7 +2,7 @@
 
 Name:          filesystem
 Version:       2.3
-Release:       4mamba
+Release:       5mamba
 Summary:       The basic directory layout for a Linux system
 Group:         System/Configuration
 Vendor:        openmamba
@@ -74,6 +74,21 @@ ln -s ../run %{buildroot}/var/run
       [ -e /run/$b ] || mv $f /run/
    done
 }
+
+%post
+/sbin/ldconfig
+if [ $1 -ge 1 ]; then
+   groupadd tty -g %{tty_groupid} 2>/dev/null || true
+fi
+:
+
+%triggerpostun -- filesystem < 2.3
+# /bin and /sbin are removed during old filesystem postun
+[ -e /bin ] || /usr/bin/ln -s usr/bin /bin
+[ -e /sbin ] || /usr/bin/ln -s usr/sbin /sbin
+:
+
+%posttrans
 [ -L /bin -a -L /sbin ] || {
   # /bin -> /usr/bin and /sbin -> /usr/sbin migration
   for f in mv rm rmdir ln; do
@@ -118,26 +133,6 @@ ln -s ../run %{buildroot}/var/run
    /usr/bin/ln -s usr/$d /$d
   done
 }
-# Add if missing for safety
-[ -e /bin ] || /usr/bin/ln -s usr/bin /bin
-[ -e /sbin ] || /usr/bin/ln -s usr/sbin /sbin
-:
-
-%post
-/sbin/ldconfig
-if [ $1 -ge 1 ]; then
-   groupadd tty -g %{tty_groupid} 2>/dev/null || true
-fi
-:
-
-%triggerpostun -p /usr/bin/bash -- filesystem < 2.3
-# /bin and /sbin are removed during old filesystem postun
-[ -e /bin ] || /usr/bin/ln -s usr/bin /bin
-[ -e /sbin ] || /usr/bin/ln -s usr/sbin /sbin
-:
-
-%posttrans -p /usr/bin/bash
-# /bin and /sbin are removed on upgrade
 [ -e /bin ] || /usr/bin/ln -s usr/bin /bin
 [ -e /sbin ] || /usr/bin/ln -s usr/sbin /sbin
 :
@@ -231,6 +226,9 @@ fi
 /usr/tmp
 
 %changelog
+* Mon Apr 19 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 2.3-5mamba
+- try performing migration in posttrans to fix problematic long-term updates 
+
 * Fri Mar 05 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 2.3-4mamba
 - use /usr/bin/bash insted of /usr/bin/sh in posttrans script
 - add triggerpostun to try to fix further problems