diff --git a/setup.py b/setup.py
index 73de061..e952e8c 100644
--- a/setup.py
+++ b/setup.py
@@ -11,11 +11,11 @@ from setuptools.command.build_ext import build_ext
 from setuptools.extension import Extension
 
 
-PACKAGE_DIR = Path(__file__).resolve().parent
+SOURCE_ROOT = Path(__file__).resolve().parent
 
 
 def detect_version() -> str:
-    pkg_info = PACKAGE_DIR / "PKG-INFO"
+    pkg_info = SOURCE_ROOT / "PKG-INFO"
     in_source_package = pkg_info.exists()
     if in_source_package:
         version_line = [line for line in pkg_info.read_text(encoding="utf-8").split("\n")
@@ -26,20 +26,20 @@ def detect_version() -> str:
         if releng_location is not None:
             sys.path.insert(0, str(releng_location.parent))
             from releng.frida_version import detect
-            version = detect(PACKAGE_DIR).name.replace("-dev.", ".dev")
+            version = detect(SOURCE_ROOT).name.replace("-dev.", ".dev")
         else:
             version = "0.0.0"
     return version
 
 
 def enumerate_releng_locations() -> Iterator[Path]:
-    source_root = os.environ.get("MESON_SOURCE_ROOT")
-    if source_root is not None:
-        parent_releng = Path(source_root) / "releng"
+    val = os.environ.get("MESON_SOURCE_ROOT")
+    if val is not None:
+        parent_releng = Path(val) / "releng"
         if releng_location_exists(parent_releng):
             yield parent_releng
 
-    local_releng = PACKAGE_DIR / "releng"
+    local_releng = SOURCE_ROOT / "releng"
     if releng_location_exists(local_releng):
         yield local_releng
 
@@ -57,10 +57,10 @@ class FridaPrebuiltExt(build_ext):
 
 class FridaDemandBuiltExt(build_ext):
     def build_extension(self, ext):
-        make = PACKAGE_DIR / "make.bat" if platform.system() == "Windows" else "make"
+        make = SOURCE_ROOT / "make.bat" if platform.system() == "Windows" else "make"
         subprocess.run([make], check=True)
 
-        outputs = [entry for entry in (PACKAGE_DIR / "build" / "src").glob("_frida.*") if entry.is_file()]
+        outputs = [entry for entry in (SOURCE_ROOT / "build" / "src").glob("_frida.*") if entry.is_file()]
         assert len(outputs) == 1
         target = self.get_ext_fullpath(ext.name)
         Path(target).parent.mkdir(parents=True, exist_ok=True)
@@ -68,7 +68,7 @@ class FridaDemandBuiltExt(build_ext):
 
 
 frida_version = detect_version()
-long_description = (PACKAGE_DIR / "README.md").read_text(encoding="utf-8")
+long_description = (SOURCE_ROOT / "README.md").read_text(encoding="utf-8")
 frida_extension = os.environ.get("FRIDA_EXTENSION", None)
 
 cmdclass = {}