diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index 9c58dbf793..b204bfbbb1 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -97,7 +97,8 @@ Everything after the -- is passed to the script.
         help=_('Export all calibre data (books/settings/plugins). Normally, you will'
             ' be asked for the export dir and the libraries to export. You can also specify them'
             ' as command line arguments to skip the questions.'
-            ' Use absolute paths for the export directory and libraries.'))
+            ' Use absolute paths for the export directory and libraries.'
+            ' The special keyword "all" can be used to export all libraries.'))
     parser.add_option('--import-calibre-data', default=False, action='store_true',
         help=_('Import previously exported calibre data'))
     parser.add_option('-s', '--shutdown-running-calibre', default=False,
diff --git a/src/calibre/utils/exim.py b/src/calibre/utils/exim.py
index 1f20a21ba0..567dfd4fb3 100644
--- a/src/calibre/utils/exim.py
+++ b/src/calibre/utils/exim.py
@@ -391,7 +391,10 @@ def run_exporter(export_dir=None, args=None):
             raise SystemExit('You must specify the export dir and libraries to export')
         export_dir = args[0]
         all_libraries = {os.path.normcase(os.path.abspath(path)):lus for path, lus in all_known_libraries().iteritems()}
-        libraries = {os.path.normcase(os.path.abspath(os.path.expanduser(path))) for path in args[1:]}
+        if 'all' in args[1:]:
+            libraries = set(all_libraries)
+        else:
+            libraries = {os.path.normcase(os.path.abspath(os.path.expanduser(path))) for path in args[1:]}
         if libraries - set(all_libraries):
             raise SystemExit('Unknown library: ' + tuple(libraries - all_libraries)[0])
         libraries = {p: all_libraries[p] for p in libraries}