diff --git a/doc/manual/opt-common.xml b/doc/manual/opt-common.xml
index 72971bd6a..329345773 100644
--- a/doc/manual/opt-common.xml
+++ b/doc/manual/opt-common.xml
@@ -343,10 +343,11 @@
 
 <varlistentry><term><option>-I</option> <replaceable>path</replaceable></term>
   
-  <listitem><para>Add a path to the Nix expression search path.  See
-  the <envar>NIX_PATH</envar> environment variable for details.  Paths
-  added through <option>-I</option> take precedence over
-  <envar>NIX_PATH</envar>.</para></listitem>
+  <listitem><para>Add a path to the Nix expression search path.  This
+  option may be given multiple times.  See the <envar>NIX_PATH</envar>
+  environment variable for information on the semantics of the Nix
+  search path.  Paths added through <option>-I</option> take
+  precedence over <envar>NIX_PATH</envar>.</para></listitem>
   
 </varlistentry>