diff --git a/builder/kojid b/builder/kojid
index 08fbfff..be9dfca 100755
--- a/builder/kojid
+++ b/builder/kojid
@@ -243,6 +243,17 @@ class BuildRoot(object):
         opts['target_arch'] = self.target_arch
         if 'mock.package_manager' in self.config['extra']:
             opts['package_manager'] = self.config['extra']['mock.package_manager']
+
+        # Append opts['plugin_conf'] to enable Mock package signing
+        if 'mock.plugin_conf.sign_enable' in self.config['extra']:
+            opts['plugin_conf'] = {}
+            opts['plugin_conf']['sign_opts'] = {}
+            opts['plugin_conf']['sign_enable'] = self.config['extra']['mock.plugin_conf.sign_enable']
+            if 'mock.plugin_conf.sign_opts.cmd' in self.config['extra']:
+                opts['plugin_conf']['sign_opts']['cmd']  = self.config['extra']['mock.plugin_conf.sign_opts.cmd']
+            if 'mock.plugin_conf.sign_opts.opts' in self.config['extra']:
+                opts['plugin_conf']['sign_opts']['opts']  = self.config['extra']['mock.plugin_conf.sign_opts.opts']
+
         output = koji.genMockConfig(self.name, self.br_arch, managed=True, **opts)
 
         #write config
diff --git a/koji/__init__.py b/koji/__init__.py
index b453017..8178c10 100644
--- a/koji/__init__.py
+++ b/koji/__init__.py
@@ -1388,6 +1388,14 @@ name=build
         parts.append("config_opts['plugin_conf'][%r] = %r\n" % (key, value))
     parts.append("\n")
 
+    # Append config_opts['plugin_conf'] to enable Mock package signing
+    append_plugin_conf = opts.get('plugin_conf')
+    parts.append("config_opts['plugin_conf']['sign_enable'] = %s\n" % append_plugin_conf['sign_enable'])
+    parts.append("config_opts['plugin_conf']['sign_opts'] = {}\n")
+    for key, value in append_plugin_conf['sign_opts'].iteritems():
+        parts.append("config_opts['plugin_conf']['sign_opts'][%r] = %r\n" % (key, value))
+    parts.append("\n")
+
     if bind_opts:
         # This line is REQUIRED for mock to work if bind_opts defined.
         parts.append("config_opts['internal_dev_setup'] = False\n")