diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d4d138b..86dbe61 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -5,10 +5,10 @@ permissions:
   contents: read # to fetch code (actions/checkout)
 jobs:
   ubuntu-minimal:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python: ['3.6', '3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
+        python: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
     steps:
     - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
     - name: set up Python
diff --git a/eessi/__init__.py b/eessi/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..8036dec
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,24 @@
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "eessi"
+description = "User-friendly command line interface to EESSI - https://eessi.io"
+readme = "README.md"
+authors = [
+    {name = "Kenneth Hoste"},
+]
+license = {file = "LICENSE"}
+dynamic = ["version"]
+requires-python = ">=3.9"
+dependencies = [
+    "typer>=0.21",
+    "rich>=14.0",
+]
+
+[project.scripts]
+eessi = "eessi.cli.main:app"
+
+[tool.setuptools.dynamic]
+version = {attr = "eessi.__version__"}
diff --git a/setup.py b/setup.py
deleted file mode 100644
index 9ef45b3..0000000
--- a/setup.py
+++ /dev/null
@@ -1,22 +0,0 @@
-from setuptools import setup
-
-with open('README.md') as fp:
-    long_descr = fp.read()
-
-setup(
-    name="eessi",
-    version="0.0.3",
-    description="User-friendly command line interface to EESSI - https://eessi.io",
-    long_description=long_descr,
-    long_description_content_type='text/markdown',
-    url="https://github.com/EESSI/eessi-cli",
-    install_requires=[
-        "typer>=0.21",
-        "rich>=14.0",
-    ],
-    packages=["eessi/cli"],
-    entry_points={
-        "console_scripts": ["eessi=eessi.cli.main:app"],
-    },
-    python_requires=">=3.9",
-)
diff --git a/src/eessi/__init__.py b/src/eessi/__init__.py
new file mode 100644
index 0000000..81f0fde
--- /dev/null
+++ b/src/eessi/__init__.py
@@ -0,0 +1 @@
+__version__ = "0.0.4"
diff --git a/eessi/cli/check.py b/src/eessi/cli/check.py
similarity index 100%
rename from eessi/cli/check.py
rename to src/eessi/cli/check.py
diff --git a/eessi/cli/init.py b/src/eessi/cli/init.py
similarity index 100%
rename from eessi/cli/init.py
rename to src/eessi/cli/init.py
diff --git a/eessi/cli/main.py b/src/eessi/cli/main.py
similarity index 100%
rename from eessi/cli/main.py
rename to src/eessi/cli/main.py
diff --git a/eessi/cli/shell.py b/src/eessi/cli/shell.py
similarity index 100%
rename from eessi/cli/shell.py
rename to src/eessi/cli/shell.py