diff --git a/src/pip/_internal/network/lazy_wheel.py b/src/pip/_internal/network/lazy_wheel.py
index f5520b4565c..08301d3d92c 100644
--- a/src/pip/_internal/network/lazy_wheel.py
+++ b/src/pip/_internal/network/lazy_wheel.py
@@ -191,10 +191,10 @@ def read(self, size: int = -1) -> bytes:
         cur = self.tell()
         if size < 0:
             assert cur <= self._length
-            size = self._length - cur
+            download_size = self._length - cur
         else:
-            size = max(size, self._chunk_size)
-        stop = min(cur + size, self._length)
+            download_size = max(size, self._chunk_size)
+        stop = min(cur + download_size, self._length)
         self._download(cur, stop - 1)
         return self._file.read(size)