diff --git a/src/ui.cpp b/src/ui.cpp
index 6684c9e..fd566c4 100644
--- a/src/ui.cpp
+++ b/src/ui.cpp
@@ -2186,8 +2186,17 @@ void open_math_dialog(App& app, int edit) {
   gtk_box_append(GTK_BOX(form), buttons);
   gtk_box_append(GTK_BOX(body), form);   // the form is the body's second child; the canvas is the file's
 
-  GtkWidget* actions = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 6);
-  GtkWidget* cancel = gtk_button_new_with_label("Cancel");
+  // The action row is the file's; what is code is what the buttons *do*, and what the second one says:
+  // "Save" edits an existing channel and "Add" makes a new one, which the file cannot know.
+  GtkWidget* actions = GTK_WIDGET(gtk_builder_get_object(ui, "math_actions"));
+  GtkWidget* cancel = GTK_WIDGET(gtk_builder_get_object(ui, "math_cancel"));
+  GtkWidget* apply = GTK_WIDGET(gtk_builder_get_object(ui, "math_apply"));
+  if (actions == nullptr || cancel == nullptr || apply == nullptr) {
+    std::fprintf(stderr, "[math] editor: math-editor.ui is missing its action row\n");
+    delete d;
+    return;
+  }
+  gtk_button_set_label(GTK_BUTTON(apply), edit >= 0 ? "Save" : "Add");
   // Named so the headless probe can click the *button* rather than call its handler: the defect
   // this guards was in the connection, which a direct call cannot see.
   g_object_set_data(G_OBJECT(window), "udpscope-math-cancel", cancel);
@@ -2196,13 +2205,7 @@ void open_math_dialog(App& app, int edit) {
   // later open then took the "already open" branch and presented it -- "I cannot edit a math
   // channel again". The same trap the other three windows in this file document.
   g_signal_connect_swapped(cancel, "clicked", G_CALLBACK(gtk_window_close), window);
-  GtkWidget* apply = gtk_button_new_with_label(edit >= 0 ? "Save" : "Add");
-  gtk_widget_add_css_class(apply, "suggested-action");
   g_signal_connect(apply, "clicked", G_CALLBACK(on_math_apply), d);
-  gtk_widget_set_halign(actions, GTK_ALIGN_END);
-  gtk_box_append(GTK_BOX(actions), cancel);
-  gtk_box_append(GTK_BOX(actions), apply);
-  gtk_box_append(GTK_BOX(outer), actions);
 
   app.math_dialog = window;
   d->apply = apply;
diff --git a/src/ui/math-editor.ui b/src/ui/math-editor.ui
index 32984f3..a74db9d 100644
--- a/src/ui/math-editor.ui
+++ b/src/ui/math-editor.ui
@@ -5,9 +5,10 @@
   The math channel editor's window and its identity row: the name the channel is called, and the unit its
   readouts carry.
 
-  The canvas below them is *declared* here but *drawn* by code (`GtkDrawingArea`), and the palette, the
-  parameter form and the buttons around it are code as well, because the form follows the selection: that is
-  the half of this dialog which is not template. The row here is the half that is.
+  The canvas below them is *declared* here but *drawn* by code (`GtkDrawingArea`); the parameter form beside
+  it and the palette are code as well, because the form follows which node is selected and the palette is the
+  operation table itself — neither is data a file should hold. What is here is the frame: the window, the
+  identity row, the body with the canvas in it, and the two buttons that end the dialog.
 
   The window's title is not here: it says which mode the editor is in ("Edit math channel" against "New math
   channel"), which the code that opens it knows and a file cannot.
@@ -61,5 +62,23 @@
         </child>
       </object>
     </child>
+    <child>
+      <object class="GtkBox" id="math_actions">
+        <property name="orientation">horizontal</property>
+        <property name="spacing">6</property>
+        <property name="halign">end</property>
+        <child>
+          <object class="GtkButton" id="math_cancel">
+            <property name="label" translatable="yes">Cancel</property>
+          </object>
+        </child>
+        <child>
+          <object class="GtkButton" id="math_apply">
+            <property name="label" translatable="yes">Add</property>
+            <property name="css-classes">suggested-action</property>
+          </object>
+        </child>
+      </object>
+    </child>
   </object>
 </interface>