diff --git a/tests/data/test237 b/tests/data/test237
index be7dfd58e..c276da917 100644
--- a/tests/data/test237
+++ b/tests/data/test237
@@ -14,13 +14,16 @@ FTP getting bad host in 227-response to PASV
 ftp://%HOSTIP:%FTPPORT/237 --disable-epsv
 </command>
 <file name="log/ftpserver.cmd">
-REPLY PASV 227 Entering Passiv Mode (1218,91,256,127,127,127)
+REPLY PASV 227 Entering Passiv Mode (1216,256,2,127,127,127)
 </file>
 </client>
 
 # Verify data after the test has been "shot"
+# The bogus address used here is chosen specifically so that when processed on
+# certain hosts with buggy resolver code, the resulting address (192.0.2.127)
+# is from an address block that is guaranteed never to be assigned (RFC3330).
 <verify>
-# curl: (15) Can't resolve new host 1218.91.256.127:32639
+# curl: (15) Can't resolve new host 1216.256.2.127:32639
 # 15 => CURLE_FTP_CANT_GET_HOST
 # some systems just don't fail on the illegal host name/address but instead
 # moves on and attempt to connect to... yes, to what?