diff --git a/nixos/doc/manual/options-to-docbook.xsl b/nixos/doc/manual/options-to-docbook.xsl
index bb65a49217f0..e81a1dc356e1 100644
--- a/nixos/doc/manual/options-to-docbook.xsl
+++ b/nixos/doc/manual/options-to-docbook.xsl
@@ -202,4 +202,10 @@
     </simplelist>
   </xsl:template>
 
+
+  <xsl:template match="function">
+    <xsl:text>λ</xsl:text>
+  </xsl:template>
+
+
 </xsl:stylesheet>