diff --git a/CHANGELOG.md b/CHANGELOG.md
index aa3e320..a59419f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,7 +3,7 @@
 We follow Semantic Versions since the `0.1.0` release.
 
 
-## Version 0.3.0 WIP
+## Version 0.3.0
 
 ### Features
 
@@ -12,6 +12,8 @@ We follow Semantic Versions since the `0.1.0` release.
 - **Breaking**: now `classes` traverses `mro` of registered types
   and fallbacks to super-types if some type is not registered
 - Adds generic typeclasses
+- Adds caching to runtime type dispatch,
+  it allows to call already resolved instances way faster
 - Adds better typeclass validation during `mypy` typechecking
 - Adds `.supports()` method to typeclass to check
   if some instance is supported in runtime
diff --git a/poetry.lock b/poetry.lock
index d760ed4..65869fd 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -384,19 +384,6 @@ python-versions = "*"
 [package.dependencies]
 flake8 = "*"
 
-[[package]]
-name = "flake8-pyi"
-version = "20.10.0"
-description = "A plugin for flake8 to enable linting .pyi files."
-category = "dev"
-optional = false
-python-versions = ">=3.6"
-
-[package.dependencies]
-attrs = "*"
-flake8 = ">=3.2.1"
-pyflakes = ">=2.1.1"
-
 [[package]]
 name = "flake8-pytest-style"
 version = "1.4.4"
@@ -1281,7 +1268,7 @@ testing = ["pytest (>=4.6)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pyt
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.7"
-content-hash = "4a6923ffcb3a09e504db754cfa74a5547a3c5af43a25453dbe39803bdf77f36b"
+content-hash = "3a79928259336082fb4f6710ebf73124a1aaef889d34edf284388893e004829b"
 
 [metadata.files]
 alabaster = [
@@ -1469,10 +1456,6 @@ flake8-polyfill = [
     {file = "flake8-polyfill-1.0.2.tar.gz", hash = "sha256:e44b087597f6da52ec6393a709e7108b2905317d0c0b744cdca6208e670d8eda"},
     {file = "flake8_polyfill-1.0.2-py2.py3-none-any.whl", hash = "sha256:12be6a34ee3ab795b19ca73505e7b55826d5f6ad7230d31b18e106400169b9e9"},
 ]
-flake8-pyi = [
-    {file = "flake8-pyi-20.10.0.tar.gz", hash = "sha256:cee3b20a5123152c697870e7e800b60e3c95eb89e272a2b63d8cf55cafb0472c"},
-    {file = "flake8_pyi-20.10.0-py2.py3-none-any.whl", hash = "sha256:ff5dfc40bffa878f6ce95bcfd9a6ad14c44b85cbe99c4864e729301bf54267f0"},
-]
 flake8-pytest-style = [
     {file = "flake8-pytest-style-1.4.4.tar.gz", hash = "sha256:3e4452be131ed040b5ffa131d53f0b28f3d062916485974c48d73572cae60c41"},
     {file = "flake8_pytest_style-1.4.4-py3-none-any.whl", hash = "sha256:0d15b61933a3ee0647bb6b442902247c728e4ec72c4a05a7fe79dc80f38a2f30"},
diff --git a/pyproject.toml b/pyproject.toml
index 839a6b5..f5c4629 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [build-system]
-requires = ["poetry>=0.12"]
-build-backend = "poetry.masonry.api"
+requires = ["poetry-core>=1.0.0"]
+build-backend = "poetry.core.masonry.api"
 
 
 [tool.nitpick]
@@ -9,7 +9,7 @@ style = "https://raw.githubusercontent.com/wemake-services/wemake-python-stylegu
 
 [tool.poetry]
 name = "classes"
-version = "0.2.0"
+version = "0.3.0"
 description = "Smart, pythonic, ad-hoc, typed polymorphism for Python"
 license = "BSD-2-Clause"
 
@@ -36,7 +36,7 @@ keywords = [
 ]
 
 classifiers = [
-  "Development Status :: 3 - Alpha",
+  "Development Status :: 4 - Beta",
   "Intended Audience :: Developers",
   "Operating System :: OS Independent",
   "Topic :: Software Development :: Libraries :: Python Modules",
@@ -52,7 +52,6 @@ mypy = "^0.902"
 
 wemake-python-styleguide = "^0.15"
 flake8-pytest-style = "^1.4"
-flake8-pyi = "^20.10"
 nitpick = "^0.26"
 
 safety = "^1.10"