diff --git a/pyproj/datadir.py b/pyproj/datadir.py
index df625fee..a2beb06c 100644
--- a/pyproj/datadir.py
+++ b/pyproj/datadir.py
@@ -70,7 +70,7 @@ def get_data_dir() -> str:
     global _VALIDATED_PROJ_DATA
     if _VALIDATED_PROJ_DATA is not None:
         return _VALIDATED_PROJ_DATA
-    internal_datadir = Path(__file__).absolute().parent / "proj_dir" / "share" / "proj"
+    internal_datadir = Path("@proj@/share/proj")
     proj_lib_dirs = os.environ.get("PROJ_DATA", os.environ.get("PROJ_LIB", ""))
     prefix_datadir = Path(sys.prefix, "share", "proj")
     conda_windows_prefix_datadir = Path(sys.prefix, "Library", "share", "proj")
diff --git a/setup.py b/setup.py
index 71fb52cd..7984a68a 100644
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,7 @@ from setuptools import Extension, setup
 PROJ_MIN_VERSION = parse_version("8.2.0")
 CURRENT_FILE_PATH = Path(__file__).absolute().parent
 BASE_INTERNAL_PROJ_DIR = Path("proj_dir")
-INTERNAL_PROJ_DIR = CURRENT_FILE_PATH / "pyproj" / BASE_INTERNAL_PROJ_DIR
+INTERNAL_PROJ_DIR = Path("@proj@")
 PROJ_VERSION_SEARCH = re.compile(r".*Rel\.\s+(?P<version>\d+\.\d+\.\d+).*")
 
 
@@ -163,7 +163,7 @@ def get_extension_modules():
     # By default we'll try to get options PROJ_DIR or the local version of proj
     proj_dir = get_proj_dir()
     library_dirs = get_proj_libdirs(proj_dir)
-    include_dirs = get_proj_incdirs(proj_dir)
+    include_dirs = get_proj_incdirs(Path("@projdev@"))
 
     proj_version = get_proj_version(proj_dir)
     check_proj_version(proj_version)
diff --git a/test/test_cli.py b/test/test_cli.py
index 7a696de7..1b9b777b 100644
--- a/test/test_cli.py
+++ b/test/test_cli.py
@@ -14,7 +14,7 @@ from pyproj.sync import _load_grid_geojson
 from test.conftest import grids_available, proj_env, tmp_chdir
 
 PYPROJ_CLI_ENDPONTS = pytest.mark.parametrize(
-    "input_command", [["pyproj"], [sys.executable, "-m", "pyproj"]]
+    "input_command", [[sys.executable, "-m", "pyproj"]]
 )