diff --git a/pep-0517.txt b/pep-0517.txt
index 4c7a3ccb5..472689b3c 100644
--- a/pep-0517.txt
+++ b/pep-0517.txt
@@ -801,6 +801,7 @@ build backend::
     import os.path
     import pathlib
     import shutil
+    import tarfile
 
     SDIST_NAME = "mypackage-0.1"
     SDIST_FILENAME = SDIST_NAME + ".tar.gz"