diff --git a/plugins/OStatus/actions/usersalmon.php b/plugins/OStatus/actions/usersalmon.php
index cd24dff3ac..1c4c64efcc 100644
--- a/plugins/OStatus/actions/usersalmon.php
+++ b/plugins/OStatus/actions/usersalmon.php
@@ -29,22 +29,44 @@ class UsersalmonAction extends SalmonAction
     {
         parent::prepare($args);
 
-        $id = $this->trimmed('id');
-
-        if (!$id) {
-            // TRANS: Client error displayed trying to perform an action without providing an ID.
-            $this->clientError(_m('No ID.'));
-        }
-
-        $this->user = User::getKV('id', $id);
-
-        if (!$this->user instanceof User) {
-            // TRANS: Client error displayed when referring to a non-existing user.
-            $this->clientError(_m('No such user.'));
-        }
+        $this->user = User::getByID($this->trimmed('id'));
 
         $this->target = $this->user->getProfile();
 
+        // Notice must either be a) in reply to a notice by this user
+        // or b) in reply to a notice to the attention of this user
+        // or c) to the attention of this user
+        // or d) reference the user as an activity:object
+
+        $notice = null;
+
+        if (!empty($this->activity->context->replyToID)) {
+            try {
+                $notice = Notice::getKV('uri', $this->activity->context->replyToID);
+            } catch (NoResultException $e) {
+                $notice = false;
+            }
+        }
+
+        if ($notice instanceof Notice &&
+                ($this->target->sameAs($notice->getProfile())
+                    || array_key_exists($this->target->getID(), $notice->getAttentionProfileIDs())
+                )) {
+            // In reply to a notice either from or mentioning this user.
+            common_debug('User is the owner or was in the attention list of thr:in-reply-to activity.');
+        } elseif (!empty($this->activity->context->attention) &&
+                   array_key_exists($this->target->getUri(), $this->activity->context->attention)) {
+            // To the attention of this user.
+            common_debug('User was in attention list of salmon slap.');
+        } elseif (!empty($this->activity->objects) && $this->activity->objects[0]->id === $this->target->getUri()) {
+            // The user is the object of this slap (unfollow for example)
+            common_debug('User URI was the id of the salmon slap object.');
+        } else {
+            common_debug('User was NOT found in salmon slap context.');
+            // TRANS: Client exception.
+            throw new ClientException(_m('The owner of this salmon endpoint was not in the context of the carried slap.'));
+        }
+
         return true;
     }
 
diff --git a/plugins/OStatus/lib/salmonaction.php b/plugins/OStatus/lib/salmonaction.php
index f7e9dde067..d1293728d2 100644
--- a/plugins/OStatus/lib/salmonaction.php
+++ b/plugins/OStatus/lib/salmonaction.php
@@ -99,40 +99,6 @@ class SalmonAction extends Action
 
         common_log(LOG_DEBUG, "Got a " . $this->activity->verb);
 
-        // Notice must either be a) in reply to a notice by this user
-        // or b) in reply to a notice to the attention of this user
-        // or c) to the attention of this user
-        // or d) reference the user as an activity:object
-
-        $notice = null;
-
-        if (!empty($this->activity->context->replyToID)) {
-            try {
-                $notice = Notice::getKV('uri', $this->activity->context->replyToID);
-            } catch (NoResultException $e) {
-                $notice = false;
-            }
-        }
-
-        if ($notice instanceof Notice &&
-                ($this->target->sameAs($notice->getProfile())
-                    || array_key_exists($this->target->getID(), $notice->getAttentionProfileIDs())
-                )) {
-            // In reply to a notice either from or mentioning this user.
-            common_debug('User is the owner or was in the attention list of thr:in-reply-to activity.');
-        } elseif (!empty($this->activity->context->attention) &&
-                   array_key_exists($this->target->getUri(), $this->activity->context->attention)) {
-            // To the attention of this user.
-            common_debug('User was in attention list of salmon slap.');
-        } elseif (!empty($this->activity->objects) && $this->activity->objects[0]->id === $this->target->getUri()) {
-            // The user is the object of this slap (unfollow for example)
-            common_debug('User URI was the id of the salmon slap object.');
-        } else {
-            common_debug('User was NOT found in salmon slap context.');
-            // TRANS: Client exception.
-            throw new ClientException(_m('The owner of this salmon endpoint was not in the context of the carried slap.'));
-        }
-
         try {
             $options = [ 'source' => 'ostatus' ];
             common_debug('Save salmon slap directly with Notice::saveActivity for actor=='.$this->actor->getID());