diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 99b3dc3..d12cf9e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,8 +31,8 @@ jobs:
       - name: Code style check (isort + Black, one order — no conflict)
         run: |
           echo "🔍 Applying isort then black (pyproject.toml: isort profile=black)..."
-          isort .
-          black .
+          python -m isort .
+          python -m black .
           echo "🔍 Checking that repo is already formatted (no diff after isort+black)..."
           git diff --exit-code || (
             echo "❌ Code style drift. Locally run: isort . && black . && git add -A && git commit -m 'style: isort + black'"
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 1b4d9a4..411601d 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -9,5 +9,6 @@ coverage>=7.0.0
 
 # Development tools
 black>=23.0.0
+isort>=5.12.0
 flake8>=6.0.0
 mypy>=1.0.0