diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index 03180cf1084..bdffb4b859e 100644
--- a/doc/src/sgml/backup.sgml
+++ b/doc/src/sgml/backup.sgml
@@ -579,7 +579,7 @@ tar -cf backup.tar /usr/local/pgsql/data
     character in the command.  The simplest useful command is something
     like:
 <programlisting>
-archive_command = 'cp -i %p /mnt/server/archivedir/%f &lt;/dev/null'  # Unix
+archive_command = 'test ! -f /mnt/server/archivedir/%f && cp %p /mnt/server/archivedir/%f'  # Unix
 archive_command = 'copy "%p" "C:\\server\\archivedir\\%f"'  # Windows
 </programlisting>
     which will copy archivable WAL segments to the directory
@@ -588,7 +588,7 @@ archive_command = 'copy "%p" "C:\\server\\archivedir\\%f"'  # Windows
     <literal>%p</> and <literal>%f</> parameters have been replaced,
     the actual command executed might look like this:
 <programlisting>
-cp -i pg_xlog/00000001000000A900000065 /mnt/server/archivedir/00000001000000A900000065 &lt;/dev/null
+test ! -f /mnt/server/archivedir/00000001000000A900000065 &amp;&amp; cp pg_xlog/00000001000000A900000065 /mnt/server/archivedir/00000001000000A900000065
 </programlisting>
     A similar command will be generated for each new file to be archived.
    </para>
@@ -617,18 +617,19 @@ cp -i pg_xlog/00000001000000A900000065 /mnt/server/archivedir/00000001000000A900
     preserve the integrity of your archive in case of administrator error
     (such as sending the output of two different servers to the same archive
     directory).
+   </para>
+
+   <para>
     It is advisable to test your proposed archive command to ensure that it
     indeed does not overwrite an existing file, <emphasis>and that it returns
-    nonzero status in this case</>.  On many Unix platforms, <command>cp
-    -i</> causes copy to prompt before overwriting a file, and
-    <literal>&lt; /dev/null</> causes the prompt (and overwriting) to
-    fail.  If your platform does not support this behavior, you should
-    add a command to test for the existence of the archive file.  For
-    example, something like:
-<programlisting>
-archive_command = 'test ! -f /mnt/server/archivedir/%f &amp;&amp; cp %p /mnt/server/archivedir/%f'
-</programlisting>
-    works correctly on most Unix variants.
+    nonzero status in this case</>.
+    The example command above for Unix ensures this by including a separate
+    <command>test</> step.  On some Unix platforms, <command>cp</> has
+    switches such as <option>-i</> that can be used to do the same thing
+    less verbosely, but you should not rely on these without verifying that
+    the right exit status is returned.  (In particular, GNU <command>cp</>
+    will return status zero when <option>-i</> is used and the target file
+    already exists, which is <emphasis>not</> the desired behavior.)
    </para>
 
    <para>