diff --git a/tabcmd/execution/global_options.py b/tabcmd/execution/global_options.py
index 1a24133c..46a277dc 100644
--- a/tabcmd/execution/global_options.py
+++ b/tabcmd/execution/global_options.py
@@ -111,11 +111,34 @@ def set_embedded_datasources_options(parser):
 
 
 # used in create extract. listed in delete-extract but makes no sense there
+def _parse_yes_no(value: str) -> bool:
+    # tabcmd Classic accepts exactly `yes`/`y`/`no`/`n` (case-insensitive) on
+    # --encrypt — see workgroup/src/silos/tableau-server/applications/
+    # app-tabcmd/src/com/tableausoftware/tabcmd/commands/CreateExtracts.java
+    # lines 79-101 in the monolith. tabcmd 2 keeps Classic's set intact (so
+    # ported scripts run) and adds `true`/`false`/`1`/`0` as a forgiving
+    # superset for users who type boolean-shaped values.
+    lowered = value.strip().lower()
+    if lowered in ("yes", "y", "true", "1"):
+        return True
+    if lowered in ("no", "n", "false", "0"):
+        return False
+    import argparse
+
+    raise argparse.ArgumentTypeError("Expected yes/y/no/n/true/false/1/0 for --encrypt, got {!r}".format(value))
+
+
 def set_encryption_option(parser):
     parser.add_argument(
         "--encrypt",
         dest="encrypt",
-        action="store_true",  # set to true IF user passes in option --encrypt
+        # Classic parity: --encrypt yes / --encrypt no. Bare --encrypt still
+        # means True (default tabcmd 2 behavior). Omitted -> False.
+        nargs="?",
+        const=True,
+        default=False,
+        type=_parse_yes_no,
+        metavar="yes|y|no|n|true|false|1|0",
         help=_("createextracts.options.encrypt"),
     )
     return parser
diff --git a/tests/parsers/test_parser_create_extracts.py b/tests/parsers/test_parser_create_extracts.py
index 94ca7a7e..505cee14 100644
--- a/tests/parsers/test_parser_create_extracts.py
+++ b/tests/parsers/test_parser_create_extracts.py
@@ -106,3 +106,62 @@ def test_create_extract_parser_missing_embedded_datasources(self):
         ]
         with self.assertRaises(SystemExit):
             args = self.parser_under_test.parse_args(mock_args)
+
+    # --encrypt Classic set is yes|y|no|n (case-insensitive) per
+    # app-tabcmd/.../CreateExtracts.java:79-101; tabcmd 2 adds
+    # true|false|1|0 on top as a forgiving superset. Bare flag still True,
+    # omitted False.
+    def _base_args(self):
+        return [commandname, "--datasource", "ds", "--project", "p", "--parent-project-path", "pp"]
+
+    def test_encrypt_omitted_is_false(self):
+        args = self.parser_under_test.parse_args(self._base_args())
+        assert args.encrypt is False, args
+
+    def test_encrypt_bare_flag_is_true(self):
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt"])
+        assert args.encrypt is True, args
+
+    def test_encrypt_yes_is_true(self):
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "yes"])
+        assert args.encrypt is True, args
+
+    def test_encrypt_no_is_false(self):
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "no"])
+        assert args.encrypt is False, args
+
+    def test_encrypt_y_is_true(self):
+        # Classic shortcut; ported scripts must keep working.
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "y"])
+        assert args.encrypt is True, args
+
+    def test_encrypt_n_is_false(self):
+        # Classic shortcut; ported scripts must keep working.
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "n"])
+        assert args.encrypt is False, args
+
+    def test_encrypt_true_is_true(self):
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "true"])
+        assert args.encrypt is True, args
+
+    def test_encrypt_false_is_false(self):
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "false"])
+        assert args.encrypt is False, args
+
+    def test_encrypt_1_is_true(self):
+        # Numeric alias in tabcmd 2's forgiving superset.
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "1"])
+        assert args.encrypt is True, args
+
+    def test_encrypt_0_is_false(self):
+        # Numeric alias in tabcmd 2's forgiving superset.
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "0"])
+        assert args.encrypt is False, args
+
+    def test_encrypt_case_insensitive(self):
+        args = self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "YES"])
+        assert args.encrypt is True, args
+
+    def test_encrypt_bad_value_rejected(self):
+        with self.assertRaises(SystemExit):
+            self.parser_under_test.parse_args(self._base_args() + ["--encrypt", "maybe"])