diff --git a/doc/stdenv.xml b/doc/stdenv.xml
index 7e04cf20fe75..9c9b61cd1dce 100644
--- a/doc/stdenv.xml
+++ b/doc/stdenv.xml
@@ -1062,7 +1062,16 @@ echo @foo@
     That is, no substitution is performed for undefined variables.</para></listitem>
   </varlistentry>
 
-  
+
+  <varlistentry xml:id='fun-substituteAllInPlace'>
+    <term><function>substituteAllInPlace</function>
+    <replaceable>file</replaceable></term>
+    <listitem><para>Like <function>substituteAll</function>, but performs
+    the substitutions in place on the file
+    <replaceable>file</replaceable>.</para></listitem>
+  </varlistentry>
+
+
   <varlistentry xml:id='fun-stripHash'>
     <term><function>stripHash</function>
     <replaceable>path</replaceable></term>