diff --git a/docs/changes.rst b/docs/changes.rst
index 25909cf30..bed3b26d1 100644
--- a/docs/changes.rst
+++ b/docs/changes.rst
@@ -131,6 +131,19 @@ The best check that everything is ok is to run a dry-run extraction::
 Changelog
 =========
 
+Version 1.1.0rc2 (not released yet)
+------------------------------------
+
+Compatibility notes:
+
+- list: corrected mix-up of "isomtime" and "mtime" formats. Previously,
+  "isomtime" was the default but produced a verbose human format,
+  while "mtime" produced a ISO-8601-like format.
+  The behaviours have been swapped (so "mtime" is human, "isomtime" is ISO-like),
+  and the default is now "mtime".
+  "isomtime" is now a real ISO-8601 format ("T" between date and time, not a space).
+
+
 Version 1.1.0rc1 (2017-07-24)
 -----------------------------
 
diff --git a/src/borg/archiver.py b/src/borg/archiver.py
index a3db174ac..0065cd820 100644
--- a/src/borg/archiver.py
+++ b/src/borg/archiver.py
@@ -1334,7 +1334,7 @@ class Archiver:
         elif args.short:
             format = "{path}{NL}"
         else:
-            format = "{mode} {user:6} {group:6} {size:8} {isomtime} {path}{extra}{NL}"
+            format = "{mode} {user:6} {group:6} {size:8} {mtime} {path}{extra}{NL}"
 
         def _list_inner(cache):
             archive = Archive(repository, key, manifest, args.location.archive, cache=cache,
@@ -3119,7 +3119,7 @@ class Archiver:
                                help='only print file/directory names, nothing else')
         subparser.add_argument('--format', '--list-format', metavar='FORMAT', dest='format',
                                help='specify format for file listing '
-                                    '(default: "{mode} {user:6} {group:6} {size:8d} {isomtime} {path}{extra}{NL}")')
+                                    '(default: "{mode} {user:6} {group:6} {size:8d} {mtime} {path}{extra}{NL}")')
         subparser.add_argument('--json', action='store_true',
                                help='Only valid for listing repository contents. Format output as JSON. '
                                     'The form of ``--format`` is ignored, '
diff --git a/src/borg/testsuite/archiver.py b/src/borg/testsuite/archiver.py
index a26bc47cf..6ae7d4710 100644
--- a/src/borg/testsuite/archiver.py
+++ b/src/borg/testsuite/archiver.py
@@ -1787,7 +1787,7 @@ class ArchiverTestCase(ArchiverTestCaseBase):
         output_warn = self.cmd('list', '--list-format', '-', test_archive)
         self.assert_in('--list-format" has been deprecated.', output_warn)
         output_1 = self.cmd('list', test_archive)
-        output_2 = self.cmd('list', '--format', '{mode} {user:6} {group:6} {size:8d} {isomtime} {path}{extra}{NEWLINE}', test_archive)
+        output_2 = self.cmd('list', '--format', '{mode} {user:6} {group:6} {size:8d} {mtime} {path}{extra}{NEWLINE}', test_archive)
         output_3 = self.cmd('list', '--format', '{mtime:%s} {path}{NL}', test_archive)
         self.assertEqual(output_1, output_2)
         self.assertNotEqual(output_1, output_3)