diff --git a/src/filewidgets/CMakeLists.txt b/src/filewidgets/CMakeLists.txt
--- a/src/filewidgets/CMakeLists.txt
+++ b/src/filewidgets/CMakeLists.txt
@@ -53,7 +53,7 @@
     GROUP_BASE_NAME KF
     VERSION ${KF5_VERSION}
     DEPRECATED_BASE_VERSION 0
-    DEPRECATION_VERSIONS 4.3 4.5 5.0 5.33
+    DEPRECATION_VERSIONS 4.3 4.5 5.0 5.33 5.66
 )
 # TODO: add support for EXCLUDE_DEPRECATED_BEFORE_AND_AT to all KIO libs
 # needs fixing of undeprecated API being still implemented using own deprecated API
diff --git a/src/filewidgets/kfilewidget.h b/src/filewidgets/kfilewidget.h
--- a/src/filewidgets/kfilewidget.h
+++ b/src/filewidgets/kfilewidget.h
@@ -353,11 +353,15 @@
      */
     void setLocationLabel(const QString &text);
 
+#if KIOFILEWIDGETS_ENABLE_DEPRECATED_SINCE(5, 66)
     /**
      * Returns a pointer to the toolbar.
+     * @deprecated since 5.66 due to no known users and leaking KXMLGui into the API.
      *
      */
+    KIOFILEWIDGETS_DEPRECATED_VERSION(5, 66, "No known user")
     KToolBar *toolBar() const;
+#endif
 
     /**
      * @returns a pointer to the OK-Button in the filedialog.
diff --git a/src/filewidgets/kfilewidget.cpp b/src/filewidgets/kfilewidget.cpp
--- a/src/filewidgets/kfilewidget.cpp
+++ b/src/filewidgets/kfilewidget.cpp
@@ -2834,10 +2834,12 @@
     }
 }
 
+#if KIOFILEWIDGETS_BUILD_DEPRECATED_SINCE(5, 66)
 KToolBar *KFileWidget::toolBar() const
 {
     return d->toolbar;
 }
+#endif
 
 void KFileWidget::setCustomWidget(QWidget *widget)
 {