diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 7312e004..edd466c5 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,5 +1,5 @@
 {
-  ".": "1.8.0",
+  ".": "1.8.1",
   "packages/loop_common": "0.0.2",
   "packages/loop_interpolation": "0.0.2",
   "packages/map2loop": "3.4.0",
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3915bbed..92635b82 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [1.8.1](https://github.com/Loop3D/LoopStructural/compare/v1.8.0...v1.8.1) (2026-08-17)
+
+
+### Bug Fixes
+
+* make stratigraphic order consistent between methods and add unit test ([#320](https://github.com/Loop3D/LoopStructural/issues/320)) ([f9cf0be](https://github.com/Loop3D/LoopStructural/commit/f9cf0be2dd33f25432ec426ccd2bcf5ebbdaf9d2))
+
 ## [1.8.0](https://github.com/Loop3D/LoopStructural/compare/v1.7.3...v1.8.0) (2026-08-17)
 
 
diff --git a/packages/loopstructural_visualisation/src/loopstructuralvisualisation/version.py b/packages/loopstructural_visualisation/src/loopstructuralvisualisation/version.py
index d3ec452c..2d986fc5 100644
--- a/packages/loopstructural_visualisation/src/loopstructuralvisualisation/version.py
+++ b/packages/loopstructural_visualisation/src/loopstructuralvisualisation/version.py
@@ -1 +1 @@
-__version__ = "0.2.0"
+__version__ = "1.8.1"
diff --git a/packages/map2loop/src/map2loop/version.py b/packages/map2loop/src/map2loop/version.py
index 903a158a..2d986fc5 100644
--- a/packages/map2loop/src/map2loop/version.py
+++ b/packages/map2loop/src/map2loop/version.py
@@ -1 +1 @@
-__version__ = "3.4.0"
+__version__ = "1.8.1"
diff --git a/pyproject.toml b/pyproject.toml
index 61d15fdd..a501eba0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = 'setuptools.build_meta'
 
 [project]
 name = 'LoopStructural'
-version = "1.8.0"
+version = "1.8.1"
 description = '3D geological modelling'
 authors = [{ name = 'Lachlan Grose', email = 'lachlan.grose@monash.edu' }]
 readme = 'README.md'