diff --git a/tests/_data/string_files/do_format_code.toml b/tests/_data/string_files/do_format_code.toml
index d652a15..62933c5 100644
--- a/tests/_data/string_files/do_format_code.toml
+++ b/tests/_data/string_files/do_format_code.toml
@@ -1260,3 +1260,7 @@ expected="def foo():\n    \"\"\"Summary.\"\"\"\n    x = 1\n    # next line has 4
 [issue_360_no_trailing_newline]
 source="def foo():\n    \"\"\"\n    Hello foo.\n    \"\"\"\n    x = 1"
 expected="def foo():\n    \"\"\"Hello foo.\"\"\"\n    x = 1"
+
+[issue_366_triple_quote_in_parens_not_docstring]
+source="X = (\n    \"\"\"#!/bin/bash\n# Ends here.\n# A second line.\n_real=\"\"\"\n    + \"y\"\n)\n"
+expected="X = (\n    \"\"\"#!/bin/bash\n# Ends here.\n# A second line.\n_real=\"\"\"\n    + \"y\"\n)\n"
diff --git a/tests/formatter/test_do_format_code.py b/tests/formatter/test_do_format_code.py
index 037ace1..b0d75dd 100644
--- a/tests/formatter/test_do_format_code.py
+++ b/tests/formatter/test_do_format_code.py
@@ -143,6 +143,7 @@
         ("issue_331_black_module_docstring", ["--black", ""]),
         ("issue_355", NO_ARGS),
         ("issue_360_no_trailing_newline", NO_ARGS),
+        ("issue_366_triple_quote_in_parens_not_docstring", NO_ARGS),
     ],
 )
 def test_do_format_code(test_key, test_args, args):