diff --git a/gnucash/gnome-utils/gnc-main-window.cpp b/gnucash/gnome-utils/gnc-main-window.cpp
index d0420fbd94..0c1825a7d3 100644
--- a/gnucash/gnome-utils/gnc-main-window.cpp
+++ b/gnucash/gnome-utils/gnc-main-window.cpp
@@ -1607,6 +1607,33 @@ gnc_main_window_update_all_titles (void)
                    nullptr);
 }
 
+/*  Callback function invoked when the user clicks on a GtkNotebook tab.
+ *
+ *  This function is needed to make it possible to close a tab
+ *  when it's clicked using the middle mouse button;
+ *  there does not seem to be a way to do this with GtkNotebook natively.
+ *
+ *  @param widget The event box in the tab, which was clicked.
+ *
+ *  @param event The event parameter describing where on the screen
+ *  the mouse was pointing when clicked, type of click, modifiers,
+ *  etc.
+ *
+ *  @param page This is the GncPluginPage corresponding to the tab.
+ *
+ *  @return Returns TRUE if this was a middle-click, meaning Gnucash
+ *  handled the click.
+ */
+static gboolean
+gnc_tab_clicked_cb(GtkWidget *widget, GdkEventButton *event, GncPluginPage *page) {
+    if (event->type == GDK_BUTTON_PRESS && event->button == 2)
+    {
+        gnc_main_window_close_page(page);
+        return TRUE;
+    }
+    return FALSE;
+}
+
 static void
 gnc_main_window_book_dirty_cb (QofBook *book,
                                gboolean dirty,
@@ -5666,22 +5693,6 @@ gnc_main_window_button_press_cb (GtkWidget *whatever,
     return FALSE;
 }
 
-/*  Callback function invoked when the user clicks on a GtkNotebook tab.
- *
- *  This function is needed to make it possible to close a tab
- *  when it's clicked using the middle mouse button;
- *  there does not seem to be a way to do this with GtkNotebook natively.
- */
-gboolean
-gnc_tab_clicked_cb(GtkWidget *widget, GdkEventButton *event, GncPluginPage *page) {
-    if (event->type == GDK_BUTTON_PRESS && event->button == 2)
-    {
-        gnc_main_window_close_page(page);
-        return TRUE;
-    }
-    return FALSE;
-}
-
 void
 gnc_main_window_all_action_set_sensitive (const gchar *action_name,
                                           gboolean sensitive)
diff --git a/gnucash/gnome-utils/gnc-main-window.h b/gnucash/gnome-utils/gnc-main-window.h
index 3376b4e6b1..5366ca9d3a 100644
--- a/gnucash/gnome-utils/gnc-main-window.h
+++ b/gnucash/gnome-utils/gnc-main-window.h
@@ -415,26 +415,6 @@ gboolean gnc_main_window_button_press_cb (GtkWidget *whatever,
         GdkEventButton *event,
         GncPluginPage *page);
 
-/*  Callback function invoked when the user clicks on a GtkNotebook tab.
- *
- *  This function is needed to make it possible to close a tab
- *  when it's clicked using the middle mouse button;
- *  there does not seem to be a way to do this with GtkNotebook natively.
- *
- *  @param widget The event box in the tab, which was clicked.
- *
- *  @param event The event parameter describing where on the screen
- *  the mouse was pointing when clicked, type of click, modifiers,
- *  etc.
- *
- *  @param page This is the GncPluginPage corresponding to the tab.
- *
- *  @return Returns TRUE if this was a middle-click, meaning Gnucash
- *  handled the click.
- */
-gboolean
-gnc_tab_clicked_cb(GtkWidget *widget, GdkEventButton *event, GncPluginPage *page);
-
 /** Callback function invoked when the user requests that Gnucash
  *  popup the contextual menu via the keyboard context-menu request
  *  key combination (Shift-F10 by default).