diff --git a/inc/activities.php b/inc/activities.php
index c0a7748..767ee6c 100644
--- a/inc/activities.php
+++ b/inc/activities.php
@@ -11,7 +11,7 @@ function get_activity( $id ) {
             'not_found', __( 'Activity not found', 'activitypub' ), array( 'status' => 404 )
         );
     }
-    $activity = json_decode( $activity_json );
+    $activity = json_decode( $activity_json, true );
     $activity['id'] = get_activity_url( $id );
     return $activity;
 }
diff --git a/inc/api.php b/inc/api.php
index 4d42dec..918625c 100644
--- a/inc/api.php
+++ b/inc/api.php
@@ -14,7 +14,7 @@ function get_actor( $request ) {
 
 function post_to_outbox( $request ) {
     $actor = $request['actor'];
-    $activity = json_decode( $request->get_body() );
+    $activity = json_decode( $request->get_body(), true );
     return \outbox\handle_activity( $actor, $activity );
 }
 
diff --git a/inc/objects.php b/inc/objects.php
index 40a5a1b..81ab117 100644
--- a/inc/objects.php
+++ b/inc/objects.php
@@ -18,7 +18,7 @@ function get_object( $id ) {
             404, __( 'Object not found', 'activitypub' ), array ( 'status' => 404 )
         );
     }
-    $object = json_decode( $object_json );
+    $object = json_decode( $object_json, true );
     $object['id'] = get_object_url( $id );
     return $object;
 }
diff --git a/inc/outbox.php b/inc/outbox.php
index 3fea279..53b94e6 100644
--- a/inc/outbox.php
+++ b/inc/outbox.php
@@ -25,7 +25,7 @@ function handle_activity( $actor, $activity ) {
     }
     switch ( $activity['type'] ) {
     case 'Create':
-        $activity = \activites\create\handle( $actor, $activity );
+        $activity = \activities\create\handle( $actor, $activity );
         break;
     case 'Update':
         break;
@@ -68,7 +68,7 @@ function persist_activity( $actor, $activity ) {
                        'actor' => $actor,
                        'activity_id' => $activity_id,
                    ) );
-    $response = new WP_REST_Response();
+    $response = new \WP_REST_Response();
     $response->set_status( 201 );
     $response->header( 'Location', $activity['id'] );
     return $response;
@@ -81,7 +81,9 @@ function create_outbox_table() {
         CREATE TABLE IF NOT EXISTS activitypub_outbox (
             id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
             actor VARCHAR(128) NOT NULL,
-            activity_id INT UNSIGNED FOREIGN KEY REFERENCES activitypub_activities(id)
+            activity_id INT UNSIGNED NOT NULL,
+            FOREIGN KEY activity_fk(activity_id)
+            REFERENCES activitypub_activities(id)
         );
         "
     );