diff --git a/mesonbuild/msetup.py b/mesonbuild/msetup.py
index e2646f9..ac0ea7f 100644
--- a/mesonbuild/msetup.py
+++ b/mesonbuild/msetup.py
@@ -191,7 +191,7 @@
     def check_unused_options(self, coredata: 'coredata.CoreData', cmd_line_options: T.Any, all_subprojects: T.Any) -> None:
         pending = coredata.optstore.pending_project_options
         errlist: T.List[str] = []
-        permitted_unknowns = ['b_vscrt', 'b_lto', 'b_lundef']
+        permitted_unknowns = ['b_vscrt', 'b_lto', 'b_lundef', 'b_ndebug']
         permitlist: T.List[str] = []
         for opt in pending:
             # Due to backwards compatibility setting build options in non-cross
diff --git a/unittests/allplatformstests.py b/unittests/allplatformstests.py
index 4c878e3..865b5e3 100644
--- a/unittests/allplatformstests.py
+++ b/unittests/allplatformstests.py
@@ -5138,3 +5138,8 @@
             'link', 'lld-link', 'mwldarm', 'mwldeppc', 'optlink', 'xilink',
         }
         self.assertEqual(cc.linker.get_accepts_rsp(), has_rsp)
+
+    def test_nonexisting_bargs(self):
+        testdir = os.path.join(self.unit_test_dir, '117 empty project')
+        args = ['-Db_ndebug=if_release']
+        self.init(testdir, extra_args=args)