diff --git a/man/newgidmap.1.xml b/man/newgidmap.1.xml
index 1e1d4ba4..ad7a186e 100644
--- a/man/newgidmap.1.xml
+++ b/man/newgidmap.1.xml
@@ -125,6 +125,9 @@
       <filename>/etc/subgid</filename> before setting
       <filename>/proc/[pid]/gid_map</filename>.
     </para>
+    <para>
+      Note that newgidmap may be used only once for a given process.
+    </para>
 
   </refsect1>
 
diff --git a/man/newuidmap.1.xml b/man/newuidmap.1.xml
index 893cd1a9..04bb14fc 100644
--- a/man/newuidmap.1.xml
+++ b/man/newuidmap.1.xml
@@ -122,6 +122,9 @@
       <filename>/etc/subuid</filename> before setting
       <filename>/proc/[pid]/uid_map</filename>.
     </para>
+    <para>
+      Note that newuidmap may be used only once for a given process.
+    </para>
   </refsect1>
 
   <refsect1 id='options'>