diff --git a/.github/workflows/conda-package-build.yml b/.github/workflows/conda-package-build.yml
index 235e496..2a6cfa5 100644
--- a/.github/workflows/conda-package-build.yml
+++ b/.github/workflows/conda-package-build.yml
@@ -14,4 +14,4 @@ jobs:
   build:
     uses: openalea/github-action-conda-build/.github/workflows/conda-package-build.yml@main
     secrets:
-      anaconda_token: ${{ secrets.ANACONDA_TOKEN }}
\ No newline at end of file
+      anaconda_token: ${{ secrets.ANACONDA_TOKEN }}
diff --git a/conda/conda_build_config.yml b/conda/conda_build_config.yml
new file mode 100644
index 0000000..4dd09ce
--- /dev/null
+++ b/conda/conda_build_config.yml
@@ -0,0 +1,21 @@
+# from conda-forge-pinning
+c_compiler:
+  - gcc                        # [linux]
+  - clang                      # [osx]
+  - vs2019                     # [win and x86_64]
+  - vs2022                     # [win and arm64]
+c_compiler_version:            # [unix]
+  - 12                         # [linux]
+  - 16                         # [osx]
+  - 10                         # [os.environ.get("CF_CUDA_ENABLED", "False") == "True" and linux]
+  - 11                         # [os.environ.get("CF_CUDA_ENABLED", "False") == "True" and linux]
+cxx_compiler:
+  - gxx                        # [linux]
+  - clangxx                    # [osx]
+  - vs2019                     # [win and x86_64]
+  - vs2022                     # [win and arm64]
+cxx_compiler_version:          # [unix]
+  - 12                         # [linux]
+  - 16                         # [osx]
+  - 10                         # [os.environ.get("CF_CUDA_ENABLED", "False") == "True" and linux]
+  - 11                         # [os.environ.get("CF_CUDA_ENABLED", "False") == "True" and linux]
diff --git a/conda/meta.yaml b/conda/meta.yaml
index 411bb20..899f9c9 100644
--- a/conda/meta.yaml
+++ b/conda/meta.yaml
@@ -9,28 +9,29 @@ build:
   number: 0
   preserve_egg_dir: True
   string: phenomenal
-  script:
-    - {{ PYTHON }} setup.py install #--single-version-externally-managed --record record.txt
+  script: 
+    - {{PYTHON}} setup.py build_ext -j{{ CPU_COUNT }}
+    - {{ PYTHON }} -m pip install . -vv
 
 requirements:
-
-  build:
-    - {{ compiler('c') }}
-    - {{ compiler("cxx") }}
-    - python 
-    - numpy
+  host:
+    - python
+    - numpy 
+    - scipy
     - cython
 
-  host:
+  build:
+    - {{ compiler('c') }} 
+    - {{ compiler("cxx") }} 
     - python
     - setuptools
-    - cython    
     - numpy
     - scipy
+    - cython
 
   run:
-    - python
-    - numpy
+    - python x.x
+    - numpy x.x
     - cython
     - numba
     - scipy
@@ -38,10 +39,10 @@ requirements:
     - scikit-learn
     - networkx
     - opencv [win or linux]
-    - opencv!=4.1.2 [osx]
+    - opencv >4.1.2 [osx]
     - matplotlib
     - vtk
-    - skan=0.10
+    - skan>=0.10
     - pywin32 [win]
 
 test:
diff --git a/setup.py b/setup.py
index f80fe57..ae7b70f 100644
--- a/setup.py
+++ b/setup.py
@@ -68,7 +68,7 @@
     packages=packages,
     package_dir={'': 'src'},
     zip_safe=False,
-    ext_modules=cythonize(extentions),
+    ext_modules=cythonize(extentions, language_level = "3"),
 
     entry_points={
         "wralea": ["openalea.phenomenal = openalea.phenomenal_wralea", ],
@@ -76,4 +76,4 @@
 
     # See MANIFEST.in
     include_package_data=True,
-    )
\ No newline at end of file
+    )