diff --git a/actions/monkeysphere b/actions/monkeysphere
index c5e6a87bc..3090cdd6d 100755
--- a/actions/monkeysphere
+++ b/actions/monkeysphere
@@ -24,7 +24,9 @@ import argparse
 import augeas
 import json
 import os
+import psutil
 import re
+import signal
 import subprocess
 
 
@@ -50,6 +52,10 @@ def parse_arguments():
     host_publish_key.add_argument(
         'key_ids', nargs='*', help='Optional list of KEYIDs')
 
+    host_cancel_publish = subparsers.add_parser(
+        'host-cancel-publish', help='Cancel a running publish operation')
+    host_cancel_publish.add_argument('pid', help='PID of the publish process')
+
     return parser.parse_args()
 
 
@@ -237,6 +243,26 @@ def subcommand_host_publish_key(arguments):
     print(output)
 
 
+def subcommand_host_cancel_publish(arguments):
+    """Kill a running publish process."""
+    process = psutil.Process(int(arguments.pid))
+
+    # Perform tight checks on the process before killing for security.
+    arguments = process.cmdline()
+    if not arguments:
+        # Process already completed
+        return
+
+    # Remove the sudo prefix if present
+    while arguments[0] == 'sudo' or arguments[0].startswith('-'):
+        arguments = arguments[1:]
+
+    if len(arguments) >= 2 and \
+       arguments[0].split('/')[-1] == 'monkeysphere' and \
+       arguments[1] == 'host-publish-key':
+        process.send_signal(signal.SIGTERM)
+
+
 def main():
     """Parse arguments and perform all duties."""
     arguments = parse_arguments()
diff --git a/plinth/modules/monkeysphere/views.py b/plinth/modules/monkeysphere/views.py
index 434bd4607..673ab9dc2 100644
--- a/plinth/modules/monkeysphere/views.py
+++ b/plinth/modules/monkeysphere/views.py
@@ -86,7 +86,8 @@ def cancel(request):
     """Cancel ongoing process."""
     global publish_process
     if publish_process:
-        publish_process.terminate()
+        actions.superuser_run(
+            'monkeysphere', ['host-cancel-publish', str(publish_process.pid)])
         publish_process = None
         messages.info(request, _('Cancelled key publishing.'))