diff --git a/core/urls.php b/core/urls.php
index 72dc1b79..61a58549 100644
--- a/core/urls.php
+++ b/core/urls.php
@@ -116,3 +116,8 @@ function make_http(string $link): string
 
     return $link;
 }
+
+function referer_or(string $dest): string
+{
+    return $_SERVER['HTTP_REFERER'] ?? $dest;
+}
diff --git a/ext/bulk_actions/main.php b/ext/bulk_actions/main.php
index 3e217c7e..6df198b3 100644
--- a/ext/bulk_actions/main.php
+++ b/ext/bulk_actions/main.php
@@ -182,10 +182,7 @@ class BulkActions extends Extension
             }
 
             $page->set_mode(PageMode::REDIRECT);
-            if (!isset($_SERVER['HTTP_REFERER'])) {
-                $_SERVER['HTTP_REFERER'] = make_link();
-            }
-            $page->set_redirect($_SERVER['HTTP_REFERER']);
+            $page->set_redirect(referer_or(make_link()));
         }
     }
 
diff --git a/ext/comment/main.php b/ext/comment/main.php
index 76f8c01e..29effc54 100644
--- a/ext/comment/main.php
+++ b/ext/comment/main.php
@@ -226,11 +226,7 @@ class CommentList extends Extension
                 send_event(new CommentDeletionEvent(int_escape($event->get_arg(1))));
                 $page->flash("Deleted comment");
                 $page->set_mode(PageMode::REDIRECT);
-                if (!empty($_SERVER['HTTP_REFERER'])) {
-                    $page->set_redirect($_SERVER['HTTP_REFERER']);
-                } else {
-                    $page->set_redirect(make_link("post/view/" . $event->get_arg(2)));
-                }
+                $page->set_redirect(referer_or(make_link("post/view/" . $event->get_arg(2))));
             }
         } else {
             $this->theme->display_permission_denied();
diff --git a/ext/image_hash_ban/main.php b/ext/image_hash_ban/main.php
index 93304c35..8140b2ef 100644
--- a/ext/image_hash_ban/main.php
+++ b/ext/image_hash_ban/main.php
@@ -105,7 +105,7 @@ class ImageBan extends Extension
                         }
 
                         $page->set_mode(PageMode::REDIRECT);
-                        $page->set_redirect($_SERVER['HTTP_REFERER']);
+                        $page->set_redirect(referer_or(make_link()));
                     }
                 } elseif ($event->get_arg(0) == "remove") {
                     $user->ensure_authed();
@@ -113,7 +113,7 @@ class ImageBan extends Extension
                     send_event(new RemoveImageHashBanEvent($input['d_hash']));
                     $page->flash("Image ban removed");
                     $page->set_mode(PageMode::REDIRECT);
-                    $page->set_redirect($_SERVER['HTTP_REFERER']);
+                    $page->set_redirect(referer_or(make_link()));
                 } elseif ($event->get_arg(0) == "list") {
                     $t = new HashBanTable($database->raw_db());
                     $t->token = $user->get_auth_token();
diff --git a/ext/not_a_tag/main.php b/ext/not_a_tag/main.php
index 52b9fee6..795059a5 100644
--- a/ext/not_a_tag/main.php
+++ b/ext/not_a_tag/main.php
@@ -113,7 +113,7 @@ class NotATag extends Extension
                         ["tag"=>$input['c_tag'], "redirect"=>$input['c_redirect']]
                     );
                     $page->set_mode(PageMode::REDIRECT);
-                    $page->set_redirect($_SERVER['HTTP_REFERER']);
+                    $page->set_redirect(referer_or(make_link()));
                 } elseif ($event->get_arg(0) == "remove") {
                     $user->ensure_authed();
                     $input = validate_input(["d_tag"=>"string"]);
@@ -123,7 +123,7 @@ class NotATag extends Extension
                     );
                     $page->flash("Image ban removed");
                     $page->set_mode(PageMode::REDIRECT);
-                    $page->set_redirect($_SERVER['HTTP_REFERER']);
+                    $page->set_redirect(referer_or(make_link()));
                 } elseif ($event->get_arg(0) == "list") {
                     $t = new NotATagTable($database->raw_db());
                     $t->token = $user->get_auth_token();
diff --git a/ext/pm/main.php b/ext/pm/main.php
index 28b9bf6c..564d4a5a 100644
--- a/ext/pm/main.php
+++ b/ext/pm/main.php
@@ -167,7 +167,7 @@ class PrivMsg extends Extension
                                 $cache->delete("pm-count-{$user->id}");
                                 log_info("pm", "Deleted PM #$pm_id", "PM deleted");
                                 $page->set_mode(PageMode::REDIRECT);
-                                $page->set_redirect($_SERVER["HTTP_REFERER"]);
+                                $page->set_redirect(referer_or(make_link()));
                             }
                         }
                     }
@@ -182,7 +182,7 @@ class PrivMsg extends Extension
                             send_event(new SendPMEvent(new PM($from_id, $_SERVER["REMOTE_ADDR"], $to_id, $subject, $message)));
                             $page->flash("PM sent");
                             $page->set_mode(PageMode::REDIRECT);
-                            $page->set_redirect($_SERVER["HTTP_REFERER"]);
+                            $page->set_redirect(referer_or(make_link()));
                         }
                     }
                     break;
diff --git a/ext/rule34/main.php b/ext/rule34/main.php
index 32d7fd20..a0c577b6 100644
--- a/ext/rule34/main.php
+++ b/ext/rule34/main.php
@@ -118,14 +118,14 @@ class Rule34 extends Extension
                     ['is_admin'=>$input['is_admin'] ? 't' : 'f', 'id'=>$input['user_id']]
                 );
                 $page->set_mode(PageMode::REDIRECT);
-                $page->set_redirect(@$_SERVER['HTTP_REFERER']);
+                $page->set_redirect(referer_or(make_link()));
             }
         }
 
         if ($event->page_matches("tnc_agreed")) {
             setcookie("ui-tnc-agreed", "true", 0, "/");
             $page->set_mode(PageMode::REDIRECT);
-            $page->set_redirect(@$_SERVER['HTTP_REFERER'] ?? "/");
+            $page->set_redirect(referer_or("/"));
         }
 
         if ($event->page_matches("admin/cache_purge")) {