diff --git a/NEWS b/NEWS
index 0d1aec9..5105226 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,7 @@
    once for each configured repository instead of once per configuration file. Additionally, the
    "repositories" interpolated variable has been changed to "repository", containing the path to the
    current repository for the hook.
+ * #515: Fix "borgmatic borg key ..." to pass parameters to Borg in correct order.
  * #516: Fix handling of TERM signal to exit borgmatic, not just forward the signal to Borg.
  * #517: Fix borgmatic exit code (so it's zero) when initial Borg calls fail but later retries
    succeed.
diff --git a/borgmatic/borg/borg.py b/borgmatic/borg/borg.py
index 59ffe21..ff3212f 100644
--- a/borgmatic/borg/borg.py
+++ b/borgmatic/borg/borg.py
@@ -21,17 +21,20 @@ def run_arbitrary_borg(
 
     try:
         options = options[1:] if options[0] == '--' else options
-        borg_command = options[0]
-        command_options = tuple(options[1:])
+
+        # Borg's "key" command has a sub-command ("export", etc.) that must follow it.
+        command_options_start_index = 2 if options[0] == 'key' else 1
+        borg_command = tuple(options[:command_options_start_index])
+        command_options = tuple(options[command_options_start_index:])
     except IndexError:
-        borg_command = None
+        borg_command = ()
         command_options = ()
 
     repository_archive = '::'.join((repository, archive)) if repository and archive else repository
 
     full_command = (
         (local_path,)
-        + ((borg_command,) if borg_command else ())
+        + borg_command
         + ((repository_archive,) if borg_command and repository_archive else ())
         + command_options
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
diff --git a/tests/unit/borg/test_borg.py b/tests/unit/borg/test_borg.py
index ffd7835..0174a91 100644
--- a/tests/unit/borg/test_borg.py
+++ b/tests/unit/borg/test_borg.py
@@ -121,3 +121,13 @@ def test_run_arbitrary_borg_without_borg_specific_parameters_does_not_raise():
     module.run_arbitrary_borg(
         repository='repo', storage_config={}, options=[],
     )
+
+
+def test_run_arbitrary_borg_passes_key_sub_command_to_borg_before_repository():
+    flexmock(module).should_receive('execute_command').with_args(
+        ('borg', 'key', 'export', 'repo'), output_log_level=logging.WARNING, borg_local_path='borg',
+    )
+
+    module.run_arbitrary_borg(
+        repository='repo', storage_config={}, options=['key', 'export'],
+    )