diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7d3e84f..47cf47e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,6 +21,9 @@ jobs:
           python -m pip install --upgrade pip
           pip install -e ".[dev]"
 
+      - name: Download spaCy model
+        run: python -m spacy download en_core_web_lg
+
       - name: Lint with ruff
         run: ruff check sentinelguard/
 
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index acd8dc4..fc8ddc2 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -43,6 +43,9 @@ jobs:
           python -m pip install --upgrade pip
           pip install -e ".[dev]"
 
+      - name: Download spaCy model
+        run: python -m spacy download en_core_web_lg
+
       - name: Run tests
         run: pytest tests/ -v --tb=short
 
diff --git a/pyproject.toml b/pyproject.toml
index 9d78a3e..54571eb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,7 +36,6 @@ dependencies = [
     "presidio-analyzer>=2.2.0",
     "presidio-anonymizer>=2.2.0",
     "spacy>=3.6.0",
-    "en-core-web-lg @ https://github.com/explosion/spacy-models/releases/download/en_core_web_lg-3.8.0/en_core_web_lg-3.8.0-py3-none-any.whl",
     # Model-based detection (HuggingFace)
     "transformers>=4.30.0",
     "torch>=2.0.0",
diff --git a/setup.py b/setup.py
index 667c987..ae0c9b4 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,42 @@
-"""Backwards-compatible setup.py for sentinelguard."""
+"""Setup with post-install hook to download spaCy model for Presidio PII detection."""
+
+import subprocess
+import sys
 from setuptools import setup
+from setuptools.command.install import install
+
+
+class PostInstallCommand(install):
+    """Post-installation: download spaCy model required by Presidio."""
+
+    def run(self):
+        install.run(self)
+        self._download_spacy_model()
+
+    def _download_spacy_model(self):
+        model = "en_core_web_lg"
+        print(f"🔍 Checking spaCy model: {model}")
+        try:
+            import spacy
+            try:
+                spacy.load(model)
+                print(f"✅ {model} — already installed")
+            except OSError:
+                print(f"⬇️  {model} — downloading...")
+                subprocess.check_call(
+                    [sys.executable, "-m", "spacy", "download", model]
+                )
+                print(f"✅ {model} — installed")
+        except ImportError:
+            print("⚠️  spaCy not installed, skipping model download")
+        except Exception as e:
+            print(f"⚠️  Could not download {model}: {e}")
+            print(f"   Run manually: python -m spacy download {model}")
+
 
 if __name__ == "__main__":
-    setup()
+    setup(
+        cmdclass={
+            "install": PostInstallCommand,
+        },
+    )