diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index fd898c7..e3747e9 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -2025,7 +2025,7 @@
                     print("link to", tarinfo.linkname, end=' ')
             print()
 
-    def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
+    def add(self, name, arcname=None, recursive=True, exclude=None, *, filter=None):
         """Add the file `name' to the archive. `name' may be any type of file
            (directory, fifo, symbolic link, etc.). If given, `arcname'
            specifies an alternative name for the file in the archive.
@@ -2082,7 +2082,7 @@
             if recursive:
                 for f in os.listdir(name):
                     self.add(os.path.join(name, f), os.path.join(arcname, f),
-                            recursive, exclude, filter)
+                            recursive, exclude, filter=filter)
 
         else:
             self.addfile(tarinfo)
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index ff02c69..94ef61c 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -919,6 +919,10 @@
             finally:
                 tar.close()
 
+            # Verify that filter is a keyword-only argument
+            with self.assertRaises(TypeError):
+                tar.add(tempdir, "empty_dir", True, None, filter)
+
             tar = tarfile.open(tmpname, "r")
             try:
                 for tarinfo in tar: