diff --git a/.github/workflows/test_package.yml b/.github/workflows/test_package.yml
index a498976..fdbc71d 100644
--- a/.github/workflows/test_package.yml
+++ b/.github/workflows/test_package.yml
@@ -6,8 +6,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest, ubuntu-latest, macos-latest]
-        embedded-py: [3.9.8, 3.11.3]
+        os: [windows-latest]
+        embedded-py: [3.11.3]
     env:
       create_pck: conan create . lumicks/testing -o embedded_python:version=${{ matrix.embedded-py }} --build=missing
     steps:
@@ -31,9 +31,5 @@ jobs:
       run: conan create ./core lumicks/testing -o embedded_python-core:version=${{ matrix.embedded-py }} --build=missing
     - name: Test baseline
       run: ${{ env.create_pck }}
-    - name: Test with numpy env
-      run: ${{ env.create_pck }} -o test_embedded_python:env=numpy
-    - name: Test with nbconvert env
-      run: ${{ env.create_pck }} -o test_embedded_python:env=nbconvert
     - name: Test with pylake env
       run: ${{ env.create_pck }} -o test_embedded_python:env=pylake
diff --git a/conanfile.py b/conanfile.py
index 955f471..6b04f38 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -76,6 +76,9 @@ def package_py_exe(self):
         else:
             return pathlib.Path(self.package_folder, "embedded_python/bin/python3")
 
+    def _run_bootstrap_py(self, command, **kwargs):
+        self.run(f"{self.bootstrap_py_exe} -E -s {command}", **kwargs)
+
     def make_package_list(self):
         """Create a list of package names based on `self.options.packages`
 
@@ -140,13 +143,29 @@ def _build_bootstrap(self):
                 file.rename(dlls / file.name)
             # We need pip to install packages
             files.download(self, "https://bootstrap.pypa.io/get-pip.py", filename="get-pip.py")
-            self.run(f"{self.bootstrap_py_exe} -E get-pip.py")
+            self._run_bootstrap_py("get-pip.py")
+
+        with open(bootstrap / "pyenv.cfg", "w") as f:
+            f.write("include-system-site-packages = false\n")
 
         # While we do need to mostly restore regular module path rules for the bootstrap, we still
         # don't want to get conflicts with packages installed in the user's home directory. We can
         # disable those via env variable. Again, this is only for bootstrapping. The final package
         # will be fully isolated via the `._pth` file.
+        self.run(f'{self.bootstrap_py_exe} -c "import sys; [print(p) for p in sys.path]; print()"')
         os.environ["PYTHONNOUSERSITE"] = "1"
+        self.run(f'{self.bootstrap_py_exe} -c "import sys; [print(p) for p in sys.path]; print()"')
+        os.environ["PYTHONSAFEPATH"] = "1"
+        self.run(f'{self.bootstrap_py_exe} -c "import sys; [print(p) for p in sys.path]; print()"')
+        self.run(
+            f"{self.bootstrap_py_exe} -c \"import os; print(os.environ.get('PYTHONSAFEPATH'))\""
+        )
+        self.run(
+            f'{self.bootstrap_py_exe} -s -E -c "import sys; [print(p) for p in sys.path]; print()"'
+        )
+        self.run(
+            f'{self.bootstrap_py_exe} -I -c "import sys; [print(p) for p in sys.path]; print()"'
+        )
 
         specs = [
             f"pip=={self.options.pip_version}",
@@ -155,12 +174,12 @@ def _build_bootstrap(self):
             f"pip-licenses=={self.options.pip_licenses_version}",
         ]
         options = "--no-warn-script-location --upgrade"
-        self.run(f"{self.bootstrap_py_exe} -E -m pip install {options} {' '.join(specs)}")
+        self._run_bootstrap_py(f"-m pip --isolated install {options} {' '.join(specs)}")
 
     def _gather_licenses(self, license_folder):
         """Gather licenses for all packages using our bootstrap environment"""
-        self.run(
-            f"{self.bootstrap_py_exe} -E -m piplicenses --python={self.package_py_exe}"
+        self._run_bootstrap_py(
+            f"-m piplicenses --python={self.package_py_exe}"
             " --with-system --from=mixed --format=plain-vertical"
             " --with-license-file --no-license-path --output-file=package_licenses.txt",
             cwd=license_folder,
@@ -195,7 +214,7 @@ def package(self):
         )
         prefix = pathlib.Path(self.package_folder, "embedded_python")
         options = f'--no-deps --ignore-installed --no-warn-script-location --prefix "{prefix}"'
-        self.run(f"{self.bootstrap_py_exe} -E -m pip install {options} -r {requirements}")
+        self._run_bootstrap_py(f"-m pip install --isolated {options} -r {requirements}")
         self._gather_licenses(license_folder)
         self._gather_packages(license_folder)