diff --git a/Sources/PersonalMessage/PM.php b/Sources/PersonalMessage/PM.php
index 058ec72dc0..24873e6a85 100644
--- a/Sources/PersonalMessage/PM.php
+++ b/Sources/PersonalMessage/PM.php
@@ -531,9 +531,8 @@ public static function get($ids, array $query_customizations = [])
 		$limit = $query_customizations['limit'] ?? count($ids);
 		$params = $query_customizations['params'] ?? [];
 
-		if (!empty($ids)) {
-			$params['ids'] = array_filter(array_unique(array_map('intval', $ids)));
-		}
+		// There will never be an ID 0, but SMF doesn't like empty arrays when you tell it to expect an array of integers...
+		$params['ids'] = empty($ids) ? [0] : array_filter(array_unique(array_map('intval', $ids)));
 
 		foreach(self::queryData($selects, $params, $joins, $where, $order, $group, $limit) as $row) {
 			$id = (int) $row['id_pm'];
diff --git a/Sources/PersonalMessage/Popup.php b/Sources/PersonalMessage/Popup.php
index 22b10cbc04..a15e9a1f63 100644
--- a/Sources/PersonalMessage/Popup.php
+++ b/Sources/PersonalMessage/Popup.php
@@ -65,7 +65,7 @@ public function show(): void
 			}
 
 			// Now, actually fetch me some PMs.
-			foreach (PM::load($pms, false) as $pm) {
+			foreach (PM::load($pms) as $pm) {
 				// Make sure we track the senders. We have some work to do for them.
 				if (!empty($pm->member_from)) {
 					$senders[] = $pm->member_from;
diff --git a/Sources/PersonalMessage/Received.php b/Sources/PersonalMessage/Received.php
index 7f20c3b537..495e56b7a2 100644
--- a/Sources/PersonalMessage/Received.php
+++ b/Sources/PersonalMessage/Received.php
@@ -524,6 +524,8 @@ public static function getRecent(int $label = -1, string $sort = 'pmr.id_pm', bo
 			return self::$recent[$paramskey];
 		}
 
+		self::$recent[$paramskey] = [];
+
 		$joins = [];
 
 		$where = [
diff --git a/Sources/PersonalMessage/Search.php b/Sources/PersonalMessage/Search.php
index 7db2d838aa..3a3ddf7062 100644
--- a/Sources/PersonalMessage/Search.php
+++ b/Sources/PersonalMessage/Search.php
@@ -321,7 +321,7 @@ public function performSearch(): void
 		// Sort out the page index.
 		Utils::$context['page_index'] = new PageIndex(
 			Config::$scripturl . '?action=pm;sa=search2;params=' . $this->compressed_params,
-			$_GET['start'],
+			(int) ($_GET['start'] ?? 0),
 			Utils::$context['num_results'],
 			$this->per_page,
 			false,