diff --git a/src/calibre/gui2/convert/pdb_output.ui b/src/calibre/gui2/convert/pdb_output.ui
index 867e50c0ff..cdaca79c8d 100644
--- a/src/calibre/gui2/convert/pdb_output.ui
+++ b/src/calibre/gui2/convert/pdb_output.ui
@@ -52,6 +52,9 @@
      <property name="text">
       <string>Output &amp;encoding:</string>
      </property>
+     <property name="buddy">
+      <cstring>opt_pdb_output_encoding</cstring>
+     </property>
     </widget>
    </item>
    <item row="1" column="1">
diff --git a/src/calibre/gui2/convert/pmlz_output.ui b/src/calibre/gui2/convert/pmlz_output.ui
index 0283e572a5..85b6d12777 100644
--- a/src/calibre/gui2/convert/pmlz_output.ui
+++ b/src/calibre/gui2/convert/pmlz_output.ui
@@ -48,6 +48,9 @@
        <property name="text">
         <string>Output &amp;encoding:</string>
        </property>
+       <property name="buddy">
+        <cstring>opt_pml_output_encoding</cstring>
+       </property>
       </widget>
      </item>
      <item>