diff --git a/CHANGES.md b/CHANGES.md
index 8a11516e..25f7893d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,16 @@
 # Changes
 
+## 0.31.2.250122
+
+### opp_env
+
+### Database (Frameworks and Models)
+
+- omnetpp: added a `nixos-recent` option so any older version of omnetpp
+  can be forced to use the latest tested nixos version as an environment
+  (corrent latest is 24.05)
+- simu5g: added v1.2.3 (for omnetpp 6.1)
+
 ## 0.31.2.241127
 
 ### opp_env
diff --git a/opp_env/database/simu5g.py b/opp_env/database/simu5g.py
index 3d64bc30..155bfdc6 100644
--- a/opp_env/database/simu5g.py
+++ b/opp_env/database/simu5g.py
@@ -46,6 +46,7 @@ def get_simu5g_project_description(simu5g_version, inet_versions, omnetpp_versio
 
 def get_project_descriptions():
     return [ get_simu5g_project_description(simu5g_version, inet_versions, omnetpp_versions) for simu5g_version, inet_versions, omnetpp_versions in [
+        ["1.2.3", ["4.5.*"], ["6.1.*"]],
         ["1.2.2", ["4.5.*"], ["6.0.*"]],
         ["1.2.1", ["4.4.*"], ["6.0.*"]],
         # ["1.2.0", ["4.3.2"], ["6.0pre10"]], -- unavailable because OMNeT++ prereleases are not kept
diff --git a/tests/smoketest_list_and_info b/tests/smoketest_list_and_info
index 986bd9a4..bfd2b263 100755
--- a/tests/smoketest_list_and_info
+++ b/tests/smoketest_list_and_info
@@ -125,6 +125,7 @@ assert_contains_line 'inet-4.5.0 omnetpp-6.0.3'
 
 run opp_env list --expand-all simu5g
 assert_num_lines 78 90
+assert_contains_line 'simu5g-1.2.3 inet-4.5.4 omnetpp-6.1.0'
 assert_contains_line 'simu5g-1.2.2 inet-4.5.4 omnetpp-6.0.3'
 assert_contains_line 'simu5g-1.2.2 inet-4.5.1 omnetpp-6.0.3'
 assert_contains_line 'simu5g-1.2.2 inet-4.5.0 omnetpp-6.0.3'
@@ -147,7 +148,7 @@ assert_contains_line 'simu5g-1.2.1 inet-4.4.1 omnetpp-6.0.0'
 assert_contains_line 'simu5g-1.2.1 inet-4.4.0 omnetpp-6.0.0'
 
 run opp_env info simu5g
-assert_num_lines 52 60
+assert_num_lines 52 80
 
 run opp_env info simu5g-1.1
 assert_num_lines 14 16