diff --git a/setup.py b/setup.py
index f4700a02..4d841418 100644
--- a/setup.py
+++ b/setup.py
@@ -57,6 +57,14 @@ class BuildBazelExtension(build_ext.build_ext):
         # explicitly call `bazel shutdown` for graceful exit
         self.spawn(["bazel", "shutdown"])
 
+    def copy_extensions_to_source(self):
+        """
+        Copy generated extensions into the source tree.
+        This is done in the ``bazel_build`` method, so it's not necessary to
+        do again in the `build_ext` base class.
+        """
+        pass
+
     def bazel_build(self, ext: BazelExtension) -> None:
         """Runs the bazel build to create the package."""
         with temp_fill_include_path("WORKSPACE"):