diff --git a/colcon_core/python_install_path.py b/colcon_core/python_install_path.py
index d5f26d15..cb08789d 100644
--- a/colcon_core/python_install_path.py
+++ b/colcon_core/python_install_path.py
@@ -18,7 +18,9 @@ def get_python_install_path(name, vars_=()):
     """
     kwargs = {}
     kwargs['vars'] = dict(vars_)
+    # Avoid deb_system because it means using --install-layout deb
+    # which ignores --prefix and hardcodes it to /usr
     if 'deb_system' in sysconfig.get_scheme_names():
-        kwargs['scheme'] = 'deb_system'
+        kwargs['scheme'] = 'posix_prefix'
 
     return Path(sysconfig.get_path(name, **kwargs))
diff --git a/colcon_core/task/python/build.py b/colcon_core/task/python/build.py
index bc5d73de..54868764 100644
--- a/colcon_core/task/python/build.py
+++ b/colcon_core/task/python/build.py
@@ -110,7 +110,6 @@ async def build(self, *, additional_hooks=None):  # noqa: D102
                 ]
                 if setup_py_data.get('data_files'):
                     cmd += ['install_data', '--install-dir', args.install_base]
-                self._append_install_layout(args, cmd)
                 completed = await run(
                     self.context, cmd, cwd=args.build_base, env=env)
             finally:
@@ -300,5 +299,9 @@ def _get_python_lib(self, args):
         return os.path.relpath(path, start=args.install_base)
 
     def _append_install_layout(self, args, cmd):
+        # Debian patches sysconfig to return a path containing dist-packages
+        # instead of site-packages when using the default install scheme.
+        # TODO(sloretz) this is potentially unused now that
+        # get_python_install_path avoids the deb_system scheme.
         if 'dist-packages' in self._get_python_lib(args):
             cmd += ['--install-layout', 'deb']
diff --git a/test/spell_check.words b/test/spell_check.words
index 8ee496aa..52eb1ced 100644
--- a/test/spell_check.words
+++ b/test/spell_check.words
@@ -41,6 +41,7 @@ getcategory
 getpid
 getpreferredencoding
 github
+hardcodes
 hookimpl
 hookwrapper
 https
@@ -100,6 +101,7 @@ setupscript
 setuptools
 shlex
 sigint
+sloretz
 stacklevel
 staticmethod
 stdeb