diff --git a/classes/Notice.php b/classes/Notice.php
index b0ead3c420..a8147e4c4d 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -373,18 +373,20 @@ class Notice extends Memcached_DataObject
             $notice->saveReplies();
         }
 
-        if (isset($groups)) {
-            $notice->saveKnownGroups($groups);
-        } else {
-            $notice->saveGroups();
-        }
-
         if (isset($tags)) {
             $notice->saveKnownTags($tags);
         } else {
             $notice->saveTags();
         }
 
+        // Note: groups may save tags, so must be run after tags are saved
+        // to avoid errors on duplicates.
+        if (isset($groups)) {
+            $notice->saveKnownGroups($groups);
+        } else {
+            $notice->saveGroups();
+        }
+
         if (isset($urls)) {
             $notice->saveKnownUrls($urls);
         } else {