diff --git a/kitty/mouse.c b/kitty/mouse.c
index ef279f185..7fc8d1fd1 100644
--- a/kitty/mouse.c
+++ b/kitty/mouse.c
@@ -320,9 +320,19 @@ handle_tab_bar_mouse(int button, int UNUSED modifiers) {
     call_boss(activate_tab_at, "Kd", global_state.callback_os_window->id, global_state.callback_os_window->mouse_x);
 }
 
+static inline bool
+mouse_in_region(Region *r) {
+    if (r->left == r->right) return false;
+	if (global_state.callback_os_window->mouse_y < r->top || global_state.callback_os_window->mouse_y > r->bottom) return false;
+	if (global_state.callback_os_window->mouse_x < r->left || global_state.callback_os_window->mouse_x > r->right) return false;
+	return true;
+}
+
 static inline Window*
 window_for_event(unsigned int *window_idx, bool *in_tab_bar) {
-    *in_tab_bar = global_state.callback_os_window->num_tabs > 1 && global_state.callback_os_window->mouse_y >= global_state.callback_os_window->viewport_height - global_state.cell_height;
+    Region central, tab_bar;
+	os_window_regions(global_state.callback_os_window, &central, &tab_bar);
+	*in_tab_bar = mouse_in_region(&tab_bar);
     if (!*in_tab_bar && global_state.callback_os_window->num_tabs > 0) {
         Tab *t = global_state.callback_os_window->tabs + global_state.callback_os_window->active_tab;
         for (unsigned int i = 0; i < t->num_windows; i++) {
diff --git a/kitty/state.c b/kitty/state.c
index 9c9255b50..b84593446 100644
--- a/kitty/state.c
+++ b/kitty/state.c
@@ -242,6 +242,21 @@ add_borders_rect(id_type os_window_id, id_type tab_id, uint32_t left, uint32_t t
 }
 
 
+void
+os_window_regions(OSWindow *os_window, Region *central, Region *tab_bar) {
+    if (os_window->num_tabs > 1) {
+        central->left = 0; central->top = 0; central->right = os_window->viewport_width - 1;
+        central->bottom = os_window->viewport_height - global_state.cell_height - 1;
+        tab_bar->left = central->left; tab_bar->right = central->right; tab_bar->top = central->bottom + 1;
+        tab_bar->bottom = os_window->viewport_height - 1;
+    } else {
+        memset(tab_bar, 0, sizeof(Region));
+        central->left = 0; central->top = 0; central->right = os_window->viewport_width - 1;
+        central->bottom = os_window->viewport_height - 1;
+    }
+}
+
+
 // Python API {{{
 #define PYWRAP0(name) static PyObject* py##name(PyObject UNUSED *self)
 #define PYWRAP1(name) static PyObject* py##name(PyObject UNUSED *self, PyObject *args)
diff --git a/kitty/state.h b/kitty/state.h
index 6c93ca75f..8e196c899 100644
--- a/kitty/state.h
+++ b/kitty/state.h
@@ -160,6 +160,7 @@ void set_os_window_title(OSWindow *w, const char *title);
 OSWindow* os_window_for_kitty_window(id_type);
 OSWindow* add_os_window();
 OSWindow* current_os_window();
+void os_window_regions(OSWindow*, Region *main, Region *tab_bar);
 bool drag_scroll(Window *, OSWindow*);
 void draw_borders(ssize_t vao_idx, unsigned int num_border_rects, BorderRect *rect_buf, bool rect_data_is_dirty, uint32_t viewport_width, uint32_t viewport_height);
 ssize_t create_cell_vao();