diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 0ee8c01..2537c1f 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.3.0"
+  ".": "0.4.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ab20699..f8b2188 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,46 @@
 # Changelog
 
+## [0.4.0](https://github.com/getyourguide/dataframe-expectations/compare/v0.3.0...v0.4.0) (2025-11-10)
+
+
+### ⚠ BREAKING CHANGES
+
+* ‼️ BREAKING CHANGE: Major codebase restructuring with new module organization. However, most changes are made to the internal modules.
+
+**What changed:**
+- All internal modules have been reorganized into a `core/` package
+- Expectation registry simplified from three-dictionary to two-dictionary structure with O(1) lookups
+- Main imports updated from `expectations_suite` to `suite`
+
+**Migration guide:**
+Update your imports to use the new module structure:
+```python
+# Before
+from dataframe_expectations.expectations_suite import DataFrameExpectationsSuite
+
+# After
+from dataframe_expectations.suite import DataFrameExpectationsSuite
+```
+
+### Features
+
+* restructure codebase with core/ module and explicit imports ([42a233a](https://github.com/getyourguide/dataframe-expectations/commit/42a233ade81fc2af3ce0462ab24f189d969756bd))
+* restructure codebase, and registry refactoring ([111bca1](https://github.com/getyourguide/dataframe-expectations/commit/111bca10eed21631938db310c562d0a2d73e810c))
+* simplified registry ([c182858](https://github.com/getyourguide/dataframe-expectations/commit/c18285874837952bf1a7af3f2d1f21613286c34f))
+
+
+### Bug Fixes
+
+* consolidate imports ([9a76467](https://github.com/getyourguide/dataframe-expectations/commit/9a76467cd63c9ba15bd4878e247aef2b631316df))
+* deleted duplicate dataclass and enums from registry ([82bec0c](https://github.com/getyourguide/dataframe-expectations/commit/82bec0ce13be1e2a1bc16fb77d0aaf91edb5692f))
+* deleted duplicate DataFrameExpectation code from expectations package ([d47eb8b](https://github.com/getyourguide/dataframe-expectations/commit/d47eb8be2eef84d820653f5ef07a35e44695c5a3))
+* import enums from types ([fa84764](https://github.com/getyourguide/dataframe-expectations/commit/fa847643a310a27e615290567d3e11fad4344977))
+* manually trigger CI for release-please PRs ([49419e6](https://github.com/getyourguide/dataframe-expectations/commit/49419e6531c9fec51a6f46f1dde20ab2e850c1db))
+* manually trigger CI for release-please PRs ([9585cf5](https://github.com/getyourguide/dataframe-expectations/commit/9585cf5d75b0e90b6f94cd14cae87922055a2212))
+* return correct version when package is built ([82ff343](https://github.com/getyourguide/dataframe-expectations/commit/82ff3435c6b6ea904a1a58b71eb6a890d80991d6))
+
+
+
 ## [0.3.0](https://github.com/getyourguide/dataframe-expectations/compare/v0.2.0...v0.3.0) (2025-11-09)
 
 
diff --git a/pyproject.toml b/pyproject.toml
index f389ee1..262667e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "dataframe-expectations"
-version = "0.3.0"
+version = "0.4.0"
 description = "Python library designed to validate Pandas and PySpark DataFrames using customizable, reusable expectations"
 readme = "README.md"
 requires-python = ">=3.10"