diff --git a/lib/types.nix b/lib/types.nix
index 70d22d91b6b..0be9db30851 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -526,7 +526,7 @@ rec {
       check = isFunction;
       merge = loc: defs:
         fnArgs: (mergeDefinitions (loc ++ [ "[function body]" ]) elemType (map (fn: { inherit (fn) file; value = fn.value fnArgs; }) defs)).mergedValue;
-      getSubOptions = elemType.getSubOptions;
+      getSubOptions = prefix: elemType.getSubOptions (prefix ++ [ "[function body]" ]);
       getSubModules = elemType.getSubModules;
       substSubModules = m: functionTo (elemType.substSubModules m);
       functor = (defaultFunctor "functionTo") // { wrapped = elemType; };
diff --git a/nixos/lib/make-options-doc/options-to-docbook.xsl b/nixos/lib/make-options-doc/options-to-docbook.xsl
index b286f7b5e2c..49b189ee303 100644
--- a/nixos/lib/make-options-doc/options-to-docbook.xsl
+++ b/nixos/lib/make-options-doc/options-to-docbook.xsl
@@ -20,7 +20,19 @@
       <title>Configuration Options</title>
       <variablelist xml:id="configuration-variable-list">
         <xsl:for-each select="attrs">
-          <xsl:variable name="id" select="concat('opt-', str:replace(str:replace(str:replace(str:replace(attr[@name = 'name']/string/@value, '*', '_'), '&lt;', '_'), '>', '_'), ':', '_'))" />
+          <xsl:variable name="id" select="
+            concat('opt-',
+              str:replace(str:replace(str:replace(str:replace(str:replace(str:replace(str:replace(
+                attr[@name = 'name']/string/@value,
+                '*', '_'),
+                '&lt;', '_'),
+                ' ', '_'),
+                '>', '_'),
+                '[', '_'),
+                ']', '_'),
+                ':', '_')
+              )
+          " />
           <varlistentry>
             <term xlink:href="#{$id}">
               <xsl:attribute name="xml:id"><xsl:value-of select="$id"/></xsl:attribute>