diff --git a/src/vocalinux/ui/settings_dialog.py b/src/vocalinux/ui/settings_dialog.py
index b418d1e..f10b4a8 100644
--- a/src/vocalinux/ui/settings_dialog.py
+++ b/src/vocalinux/ui/settings_dialog.py
@@ -2918,6 +2918,15 @@ class SettingsDialog(Gtk.Dialog):
 
         footer.pack_start(self.test_output_revealer, False, False, 0)
 
+        # Separate Close from the dictation-test controls so it reads as
+        # dialog chrome, not as part of Test Dictation (#651).
+        close_separator = Gtk.Separator(orientation=Gtk.Orientation.HORIZONTAL)
+        close_separator.set_margin_start(8)
+        close_separator.set_margin_end(8)
+        close_separator.set_margin_top(2)
+        close_separator.set_margin_bottom(2)
+        footer.pack_start(close_separator, False, False, 0)
+
         # In-window Close so the dialog can always be dismissed, even on WMs
         # that hide the title-bar close button for Gtk.Dialog windows (#323).
         close_button = Gtk.Button(label="Close")
diff --git a/tests/test_settings_dialog.py b/tests/test_settings_dialog.py
index 73008bd..749480b 100644
--- a/tests/test_settings_dialog.py
+++ b/tests/test_settings_dialog.py
@@ -859,6 +859,14 @@ class TestSettingsNavigation(unittest.TestCase):
         # No persistent bottom strip below the pages
         self.assertNotIn("def _build_status_strip(self):", self.source_code)
 
+    def test_close_button_separated_from_dictation_test(self):
+        """Close sits below a separator so it reads as dialog chrome (#651)."""
+        footer_body = self.source_code.split("def _build_sidebar_footer")[1].split("\n    def ")[0]
+        after_test = footer_body.split("footer.pack_start(self.test_output_revealer")[1]
+        before_close = after_test.split('close_button = Gtk.Button(label="Close")')[0]
+        self.assertIn("Gtk.Separator", before_close)
+        self.assertIn("footer.pack_start(close_separator", before_close)
+
     def test_sidebar_icons_use_adwaita_names(self):
         """Sidebar icons must resolve in the stock Adwaita theme."""
         for icon in [