diff --git a/src/plugins/book.glade b/src/plugins/book.glade
index 607990de6..713a1bf67 100644
--- a/src/plugins/book.glade
+++ b/src/plugins/book.glade
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <interface>
-  <requires lib="gtk+" version="2.16"/>
+  <!-- interface-requires gtk+ 2.12 -->
   <!-- interface-naming-policy toplevel-contextual -->
   <object class="GtkWindow" id="top">
     <property name="width_request">600</property>