diff --git a/.github/scripts/check_version.py b/.github/scripts/check_version.py
new file mode 100644
index 000000000..f8fe4bbc3
--- /dev/null
+++ b/.github/scripts/check_version.py
@@ -0,0 +1,130 @@
+#!/usr/bin/env python3
+import os
+import re
+import sys
+from datetime import datetime
+
+import tomli
+
+
+def get_version_from_toml(file_path):
+    """Extract version from pyproject.toml"""
+    data = {}
+    try:
+        with open(file_path, "rb") as f:
+            data = tomli.load(f)
+        return data["tool"]["poetry"]["version"]
+    except KeyError:
+        # Try different possible locations for version
+        try:
+            return data["project"]["version"]
+        except KeyError:
+            print(f"Error: Could not find version in {file_path}")
+            sys.exit(1)
+
+
+def is_valid_yyyymmpp(version_str):
+    """Check if version string follows YYYY.MM.PP format"""
+    pattern = r"^(\d{4})\.(\d{1,2})\.(\d{1,2})$"
+    match = re.match(pattern, version_str)
+    if not match:
+        return False
+
+    year, month, patch = map(int, match.groups())
+
+    # Validate date components
+    if not (1900 <= year <= 2100):  # Reasonable year range
+        return False
+    if not (1 <= month <= 12):  # Valid month
+        return False
+    if not (0 <= patch <= 99):  # Reasonable patch range
+        return False
+
+    return True
+
+
+def parse_yyyymmpp_version(version_str):
+    """Parse YYYY.MM.PP version into components"""
+    pattern = r"^(\d{4})\.(\d{1,2})\.(\d{1,2})$"
+    match = re.match(pattern, version_str)
+    if not match:
+        raise ValueError(f"Invalid YYYY.MM.PP format: {version_str}")
+
+    year, month, patch = map(int, match.groups())
+    return year, month, patch
+
+
+def compare_versions(base_version, pr_version):
+    """Compare versions and check if PR version is an increment"""
+    if not is_valid_yyyymmpp(pr_version):
+        print(f"❌ PR version '{pr_version}' is not a valid YYYY.MM.PP version")
+        print("Expected format: YYYY.MM.PP (e.g., 2025.8.1)")
+        return False
+
+    try:
+        base_year, base_month, base_patch = parse_yyyymmpp_version(base_version)
+        pr_year, pr_month, pr_patch = parse_yyyymmpp_version(pr_version)
+
+        # Get current date for validation
+        current_date = datetime.now()
+        current_year = current_date.year
+        current_month = current_date.month
+
+        # Check if year is current
+        if pr_year < current_year:
+            print(
+                f"❌ Error: PR version year {pr_year} is in the past compared to current year {current_year}"
+            )
+            return False
+
+        # Check if month is current
+        if pr_month < current_month:
+            print(
+                f"❌ Error: PR version month {pr_month} is in the past compared to current month {current_month}"
+            )
+            return False
+
+        # Check if patch version is higher
+        if pr_patch <= base_patch and pr_year == base_year and pr_month == base_month:
+            print(
+                f"❌ Error: new version {pr_patch} is not greater than base patch {base_patch}"
+            )
+            return False
+
+    except Exception as e:
+        print(f"❌ Error comparing versions: {e}")
+        return False
+
+    return True
+
+
+def main():
+    # Get the base branch version (main)
+    os.system("git fetch origin main:main")
+
+    # Get PR version
+    pr_version = get_version_from_toml("pyproject.toml")
+    print(f"PR version: {pr_version}")
+
+    # Get base version from main branch
+    os.system("git checkout main -- pyproject.toml 2>/dev/null || true")
+    base_version = get_version_from_toml("pyproject.toml")
+    print(f"Base version: {base_version}")
+
+    # Validate base version format
+    if not is_valid_yyyymmpp(base_version):
+        print(
+            f"⚠️  Warning: Base version '{base_version}' doesn't follow YYYY.MM.PP format"
+        )
+
+    # Check if version is incremented
+    if compare_versions(base_version, pr_version):
+        print("✅ Version increment check passed!")
+        sys.exit(0)
+    else:
+        print("❌ Version increment check failed!")
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/.github/workflows/check-version.yml b/.github/workflows/check-version.yml
new file mode 100644
index 000000000..5844ae0c8
--- /dev/null
+++ b/.github/workflows/check-version.yml
@@ -0,0 +1,30 @@
+name: Check Version Increment
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  check-version:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.x"
+
+      - name: Install dependencies
+        run: pip install tomli
+
+      - name: Check version increment
+        run: |
+          python .github/scripts/check_version.py
diff --git a/pyproject.toml b/pyproject.toml
index 6e1f72ad3..bf3711950 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "haddock3"
-version = "2025.8.1"
+version = "2025.9.0"
 description = "HADDOCK3"
 readme = "README.md"
 authors = [{ name = "BonvinLab", email = "bonvinlab.support@uu.nl" }]