diff --git a/gatelock/gatelock/_scrollable.py b/gatelock/gatelock/_scrollable.py
index 334691f..387ffc1 100644
--- a/gatelock/gatelock/_scrollable.py
+++ b/gatelock/gatelock/_scrollable.py
@@ -344,16 +344,28 @@ class ScrollableSurface:
         self.canvas.yview_moveto(1.0)
 
     def _track_focus(self, parent: tk.Misc) -> None:
-        """Bind <FocusIn> on every descendant, each exactly once.
+        """Bind <FocusIn> and the wheel on every descendant, each exactly once.
 
         A repaint destroys and rebuilds the widgets, so this re-runs per
         screen; the WeakSet is what keeps a second :meth:`finalize` on the
         *same* widgets from stacking a second handler on each of them, and
         drops entries as the widgets are destroyed.
+
+        The wheel has to be bound per descendant because Tk dispatches through
+        *bindtags*, not the parent chain: a child's tags are ``(itself, its
+        class, the toplevel, "all")``, so an event over a Label never reaches
+        a binding on ``content``. Content that fills its viewport covers that
+        frame completely, which means wheel-over-text -- the only way anyone
+        actually scrolls with a mouse -- would do nothing. The donor this
+        replaced reached for ``bind_all`` instead, which works but installs
+        the handler on *every* widget in the application, including other
+        windows' scroll regions.
         """
         for child in parent.winfo_children():
             if child not in self._focus_bound:
                 child.bind("<FocusIn>", self._on_descendant_focus, add="+")
+                child.bind(_WHEEL_UP, self._line_up, add="+")
+                child.bind(_WHEEL_DOWN, self._line_down, add="+")
                 self._focus_bound.add(child)
             self._track_focus(child)
 
diff --git a/gatelock/gatelock/tests/test_scrollable.py b/gatelock/gatelock/tests/test_scrollable.py
index c5f01a8..6964207 100644
--- a/gatelock/gatelock/tests/test_scrollable.py
+++ b/gatelock/gatelock/tests/test_scrollable.py
@@ -327,3 +327,37 @@ def test_scroll_into_view_holds_still_for_a_widget_in_the_middle(
     surface.scroll_into_view(middle)
 
     assert _offset(surface) == before
+
+
+def test_the_wheel_scrolls_from_over_the_content(surface: ScrollableSurface) -> None:
+    """Wheel-over-text scrolls, which is the only way anyone uses a mouse here.
+
+    Tk dispatches through *bindtags*, not the parent chain: a child's tags are
+    ``(itself, its class, the toplevel, "all")``, so a binding on ``content``
+    is never consulted for an event over a Label sitting on top of it. Content
+    that fills the viewport covers that frame entirely, so binding the wheel
+    only on the canvas and the content frame makes wheel scrolling dead
+    everywhere the user would actually point.
+    """
+    child = surface.content.winfo_children()[10]
+    before = surface.canvas.yview()[0]
+
+    child.event_generate("<Button-5>")
+    surface.canvas.update()
+
+    assert surface.canvas.yview()[0] > before
+
+
+def test_the_wheel_scrolls_back_up_from_over_the_content(
+    surface: ScrollableSurface,
+) -> None:
+    """The up notch is bound on descendants too, not just the down one."""
+    child = surface.content.winfo_children()[10]
+    child.event_generate("<Button-5>")
+    surface.canvas.update()
+    scrolled = surface.canvas.yview()[0]
+
+    child.event_generate("<Button-4>")
+    surface.canvas.update()
+
+    assert surface.canvas.yview()[0] < scrolled