diff --git a/.github/workflows/release_schedule.yaml b/.github/workflows/release_schedule.yaml
deleted file mode 100644
index dabdb70..0000000
--- a/.github/workflows/release_schedule.yaml
+++ /dev/null
@@ -1,71 +0,0 @@
-name: Generate release schedule artifacts
-on:
-  schedule:
-    # At 00:00 on day-of-month 2 in every 3rd month. (i.e. every quarter)
-    # 2nd is chosen to avoid fencepost errors
-    - cron: "0 0 2 */3 *"
-  push:
-    branches:
-      - "main"
-  # On demand
-  workflow_dispatch:
-
-jobs:
-  create-artifacts:
-    runs-on: ubuntu-latest
-    permissions:
-      contents: write
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v5
-        with:
-          # We're going to make a tag that we can we release so we'll need the full history for that
-          fetch-depth: 0
-
-      - uses: prefix-dev/setup-pixi@v0.9.2
-        with:
-          pixi-version: "v0.49.0"
-
-      - name: Generate artifacts
-        run: |
-          pixi run generate-schedule --locked
-
-      - name: Test json artifact
-        run: |
-          cat schedule.json | jq
-
-      - name: setup git
-        run: |
-          # git will complain if we don't do this first
-          git config user.name "github-actions[bot]"
-          git config user.email "github-actions[bot]@users.noreply.github.com"
-
-      - name: determine tag name
-        id: tag_name
-        run: |
-          echo "TAG_NAME=$(date '+%Y-Q%q')" >> "$GITHUB_OUTPUT"
-      - name: Commit artifacts and create tag
-        env:
-          GH_TOKEN: ${{ secrets.RELEASE_PAT }}
-        run: |
-          git add -f schedule.md chart.md schedule.json
-          git commit -m "generate schedule for ${{ steps.tag_name.outputs.TAG_NAME }} release" || echo "No changes to commit"
-          git tag ${{ steps.tag_name.outputs.TAG_NAME }}
-          git push origin main
-          git push origin tag ${{ steps.tag_name.outputs.TAG_NAME }}
-
-      - name: Publish github release
-        uses: softprops/action-gh-release@v2
-        env:
-          GH_TOKEN: ${{ secrets.RELEASE_PAT }}
-        with:
-          generate_release_notes: true
-          tag_name: ${{ steps.tag_name.outputs.TAG_NAME }}
-          make_latest: true
-          files: |
-            schedule.md
-            chart.md
-            schedule.json
-
-permissions:
-  contents: write
diff --git a/action.yaml b/action.yaml
index 3cfa502..ddbdbd6 100644
--- a/action.yaml
+++ b/action.yaml
@@ -35,19 +35,19 @@ runs:
   using: "composite"
   steps:
     - name: Checkout code
-      uses: actions/checkout@v6
+      uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
     - name: Set up Git
       shell: bash
       run: |
         git config user.name "Scientific Python [bot]"
         git config user.email "scientific-python@users.noreply.github.com"
-    - uses: prefix-dev/setup-pixi@v0.9.3
+    - uses: prefix-dev/setup-pixi@82d477f15f3a381dbcc8adc1206ce643fe110fb7 # v0.9.3
       name: Setup Pixi
       with:
         pixi-version: v0.49.0
         manifest-path: ${{ github.action_path }}/pyproject.toml
     - name: Fetch Schedule from release
-      uses: robinraju/release-downloader@v1.3
+      uses: robinraju/release-downloader@daf26c55d821e836577a15f77d86ddc078948b05 # v1.12
       with:
         repository: "savente93/SPEC0-schedule"
         latest: true
@@ -71,7 +71,7 @@ runs:
         fi
     - name: Create Pull Request
       if: ${{ fromJSON(inputs.create_pr) && fromJSON(steps.changes.outputs.changes_detected) }}
-      uses: peter-evans/create-pull-request@v7
+      uses: peter-evans/create-pull-request@84ae59a2cdc2258d6fa0732dd66352dddae2a412 # v7.0.2
       with:
         token: ${{ inputs.token }}
         commit-message: ${{ inputs.commit_msg }}
diff --git a/spec0_action/__init__.py b/spec0_action/__init__.py
index 85307fb..c5a422b 100644
--- a/spec0_action/__init__.py
+++ b/spec0_action/__init__.py
@@ -23,7 +23,7 @@ def update_pyproject_dependencies(dependencies: dict, schedule: SupportSchedule)
     # Iterate by idx because we want to update it inplace
     for i in range(len(dependencies)):
         dep_str = dependencies[i]
-        pkg, extras, spec = parse_pep_dependency(dep_str)
+        pkg, extras, spec, env = parse_pep_dependency(dep_str)
 
         if isinstance(spec, Url) or pkg not in schedule["packages"]:
             continue
@@ -36,9 +36,9 @@ def update_pyproject_dependencies(dependencies: dict, schedule: SupportSchedule)
             continue
 
         if not extras:
-            new_dep_str = f"{pkg}{repr_spec_set(spec)}"
+            new_dep_str = f"{pkg}{repr_spec_set(spec)}{env or ''}"
         else:
-            new_dep_str = f"{pkg}{extras}{repr_spec_set(spec)}"
+            new_dep_str = f"{pkg}{extras}{repr_spec_set(spec)}{env or ''}"
 
         dependencies[i] = new_dep_str
 
diff --git a/spec0_action/parsing.py b/spec0_action/parsing.py
index 85575bf..c4bbf57 100644
--- a/spec0_action/parsing.py
+++ b/spec0_action/parsing.py
@@ -12,7 +12,9 @@
 Url: TypeAlias = ParseResult
 
 # Slightly modified version of https://packaging.python.org/en/latest/specifications/dependency-specifiers/#names
-PEP_PACKAGE_IDENT_RE = compile(r"(?im)^([A-Z0-9][A-Z0-9._-]*)(\[[A-Z0-9._,-]+\])?(.*)$")
+PEP_PACKAGE_IDENT_RE = compile(
+    r"(?im)^([A-Z0-9][A-Z0-9._-]*)(\[[A-Z0-9._,-]+\])?([^;]*)(;.*)?$"
+)
 
 
 class SupportSchedule(TypedDict):
@@ -64,12 +66,12 @@ def read_schedule(path: Path | str) -> Sequence[SupportSchedule]:
 
 def parse_pep_dependency(
     dep_str: str,
-) -> Tuple[str, str | None, SpecifierSet | Url | None]:
+) -> Tuple[str, str | None, SpecifierSet | Url | None, str | None]:
     match = PEP_PACKAGE_IDENT_RE.match(dep_str)
     if match is None:
         raise ValueError("Could not find any valid python package identifier")
 
-    pkg, extras, spec_str = match.groups()
+    pkg, extras, spec_str, env = match.groups()
 
     extras = extras or None
 
@@ -80,7 +82,7 @@ def parse_pep_dependency(
     else:
         spec = SpecifierSet(spec_str)
 
-    return (pkg, extras, spec)
+    return (pkg, extras, spec, env)
 
 
 def is_url_spec(str_spec: str | None) -> bool:
diff --git a/tests/test_data/pyproject.toml b/tests/test_data/pyproject.toml
index f289a6f..9198b2a 100644
--- a/tests/test_data/pyproject.toml
+++ b/tests/test_data/pyproject.toml
@@ -8,9 +8,13 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "setuptools_test"
+version         = "0.1.0"
 requires-python = ">=3.11"
 dependencies = [
-  'numpy>=1.20.0,<2',
   'pandas>=1.0.0,<3',
   'xarray>=2021.1.0',
+  "ipython>=8.7.0,<4",
+  "numpy[foo,bar]>=1.10.0,<2",
+  "scikit-learn>1.2,<1.4;sys_platform=='win32'",
+  "scikit-learn>1.2;sys_platform!='win32'"
 ]
diff --git a/tests/test_data/pyproject_pixi.toml b/tests/test_data/pyproject_pixi.toml
index b06e4c5..959d181 100644
--- a/tests/test_data/pyproject_pixi.toml
+++ b/tests/test_data/pyproject_pixi.toml
@@ -4,7 +4,12 @@ name            = "tests"
 description     = "This is just a dummy package for testing the spec 0 update github action and should not be used"
 requires-python = ">=3.10"
 version         = "0.1.0"
-dependencies    = ["ipython>=8.7.0,<4", "numpy[foo,bar]>=1.10.0,<2"]
+dependencies    = [
+    "ipython>=8.7.0,<4",
+    "numpy[foo,bar]>=1.10.0,<2",
+    "scikit-learn>1.2,<1.4;sys_platform=='win32'",
+    "scikit-learn>1.2;sys_platform!='win32'"
+]
 
 [build-system]
 build-backend = "hatchling.build"
diff --git a/tests/test_data/pyproject_pixi_updated.toml b/tests/test_data/pyproject_pixi_updated.toml
index a780ef7..21e724b 100644
--- a/tests/test_data/pyproject_pixi_updated.toml
+++ b/tests/test_data/pyproject_pixi_updated.toml
@@ -4,8 +4,12 @@ name            = "tests"
 description     = "This is just a dummy package for testing the spec 0 update github action and should not be used"
 requires-python = ">=3.11"
 version         = "0.1.0"
-dependencies    = ["ipython>=8.8.0,<4", "numpy[foo,bar]>=1.25.0,<2"]
-
+dependencies    = [
+    "ipython>=8.8.0,<4",
+    "numpy[foo,bar]>=1.25.0,<2",
+    "scikit-learn>=1.3.0,<1.4;sys_platform=='win32'",
+    "scikit-learn>=1.3.0;sys_platform!='win32'"
+]
 [build-system]
 build-backend = "hatchling.build"
 requires      = ["hatchling"]
diff --git a/tests/test_data/pyproject_updated.toml b/tests/test_data/pyproject_updated.toml
index 8698dbb..83741ec 100644
--- a/tests/test_data/pyproject_updated.toml
+++ b/tests/test_data/pyproject_updated.toml
@@ -8,9 +8,13 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "setuptools_test"
+version         = "0.1.0"
 requires-python = ">=3.11"
 dependencies = [
-  'numpy>=1.25.0,<2',
   'pandas>=1.0.0,<3',
   'xarray>=2023.1.0',
+  "ipython>=8.8.0,<4",
+  "numpy[foo,bar]>=1.25.0,<2",
+  "scikit-learn>=1.3.0,<1.4;sys_platform=='win32'",
+  "scikit-learn>=1.3.0;sys_platform!='win32'"
 ]
diff --git a/tests/test_parsing.py b/tests/test_parsing.py
index dfdf253..3ba094f 100644
--- a/tests/test_parsing.py
+++ b/tests/test_parsing.py
@@ -22,46 +22,61 @@ def test_parsing_incorrect():
 
 def test_pep_dependency_parsing():
     matplotlib_str = "matplotlib"
-    pkg, features, spec = parse_pep_dependency(matplotlib_str)
+    pkg, features, spec, env = parse_pep_dependency(matplotlib_str)
 
     assert pkg == "matplotlib", pkg
     assert features is None, features
     assert spec is None, spec
+    assert env is None, env
 
 
 def test_pep_dependency_parsing_with_spec_and_optional_dep():
     matplotlib_str = "matplotlib[foo,bar]>=3.7.0,<4"
-    pkg, features, spec = parse_pep_dependency(matplotlib_str)
+    pkg, features, spec, env = parse_pep_dependency(matplotlib_str)
 
     assert pkg == "matplotlib", pkg
     assert features == "[foo,bar]", features
     assert spec == SpecifierSet(">=3.7.0,<4"), spec
+    assert env is None, env
 
 
 def test_pep_dependency_parsing_with_spec():
     matplotlib_str = "matplotlib>=3.7.0,<4"
-    pkg, features, spec = parse_pep_dependency(matplotlib_str)
+    pkg, features, spec, env = parse_pep_dependency(matplotlib_str)
 
     assert pkg == "matplotlib", pkg
     assert features is None, features
     assert spec == SpecifierSet(">=3.7.0,<4"), spec
+    assert env is None, env
 
 
 def test_pep_dependency_parsing_with_url_spec():
     dep_str = "matplotlib @ https://github.com/pypa/pip/archive/1.3.1.zip#sha1=da9234ee9982d4bbb3c72346a6de940a148ea686"
-    pkg, features, spec = parse_pep_dependency(dep_str)
+    pkg, features, spec, env = parse_pep_dependency(dep_str)
 
     assert pkg == "matplotlib", pkg
     assert features is None, features
     assert spec == urlparse(
         " https://github.com/pypa/pip/archive/1.3.1.zip#sha1=da9234ee9982d4bbb3c72346a6de940a148ea686"
     ), spec
+    assert env is None, env
 
 
 def test_pep_dependency_parsing_extra_restrictions():
     matplotlib_str = "matplotlib>=3.7.0,<4,!=3.8.14"
-    pkg, features, spec = parse_pep_dependency(matplotlib_str)
+    pkg, features, spec, env = parse_pep_dependency(matplotlib_str)
 
     assert pkg == "matplotlib", pkg
     assert features is None, features
     assert spec == SpecifierSet("!=3.8.14,<4,>=3.7.0"), spec
+    assert env is None, env
+
+
+def test_pep_dependency_parsing_with_environment_marker():
+    matplotlib_str = "matplotlib>=3.7.0,<4;sys_platform != 'win32'"
+    pkg, features, spec, env = parse_pep_dependency(matplotlib_str)
+
+    assert pkg == "matplotlib", pkg
+    assert features is None, features
+    assert spec == SpecifierSet(">=3.7.0,<4"), spec
+    assert env == ";sys_platform != 'win32'", env