diff --git a/app/Member/FilterScope.php b/app/Member/FilterScope.php
index 8bfd5e18..c39d6799 100644
--- a/app/Member/FilterScope.php
+++ b/app/Member/FilterScope.php
@@ -133,6 +133,10 @@ class FilterScope extends Filter
         return "$key NOT IN [{$valueString}]";
     }
 
+    /**
+     * @param array{group_ids: array<int, int>, subactivity_ids: array<int, int>, activity_ids: array<int, int>} $membership
+     * @return Collection<int, string>
+     */
     protected function possibleValuesForMembership(array $membership): Collection
     {
         return $this->combinations($membership['group_ids'], $membership['activity_ids'], $membership['subactivity_ids'])
@@ -140,7 +144,8 @@ class FilterScope extends Filter
     }
 
     /**
-     * @return Collection<int, mixed>
+     * @param array<int, array<int, int>> $parts
+     * @return Collection<int, array<int, int>>
      */
     protected function combinations(...$parts): Collection
     {
@@ -148,7 +153,8 @@ class FilterScope extends Filter
         $otherParts = $parts;
 
         if (!count($otherParts)) {
-            return collect(array_map(fn ($p) => [$p], $firstPart));
+            /** @var Collection<int, Collection<int, int>> */
+            return collect($firstPart)->map(fn ($p) => [$p]);
         }
 
         /** @var Collection<int, mixed> */
diff --git a/composer.lock b/composer.lock
index a27b934d..f0935ea3 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4637,16 +4637,16 @@
         },
         {
             "name": "league/mime-type-detection",
-            "version": "1.14.0",
+            "version": "1.15.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/thephpleague/mime-type-detection.git",
-                "reference": "b6a5854368533df0295c5761a0253656a2e52d9e"
+                "reference": "ce0f4d1e8a6f4eb0ddff33f57c69c50fd09f4301"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/thephpleague/mime-type-detection/zipball/b6a5854368533df0295c5761a0253656a2e52d9e",
-                "reference": "b6a5854368533df0295c5761a0253656a2e52d9e",
+                "url": "https://api.github.com/repos/thephpleague/mime-type-detection/zipball/ce0f4d1e8a6f4eb0ddff33f57c69c50fd09f4301",
+                "reference": "ce0f4d1e8a6f4eb0ddff33f57c69c50fd09f4301",
                 "shasum": ""
             },
             "require": {
@@ -4677,7 +4677,7 @@
             "description": "Mime-type detection for Flysystem",
             "support": {
                 "issues": "https://github.com/thephpleague/mime-type-detection/issues",
-                "source": "https://github.com/thephpleague/mime-type-detection/tree/1.14.0"
+                "source": "https://github.com/thephpleague/mime-type-detection/tree/1.15.0"
             },
             "funding": [
                 {
@@ -4689,7 +4689,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-10-17T14:13:20+00:00"
+            "time": "2024-01-28T23:22:08+00:00"
         },
         {
             "name": "league/oauth2-server",
diff --git a/phpstan.neon b/phpstan.neon
index ab371dd4..1423a9a7 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -531,3 +531,13 @@ parameters:
             message: "#^Using nullsafe property access on non\\-nullable type App\\\\Invoice\\\\BillKind\\. Use \\-\\> instead\\.$#"
             count: 1
             path: app/Member/Member.php
+
+        -
+            message: "#^Method App\\\\Member\\\\FilterScope\\:\\:combinations\\(\\) should return Illuminate\\\\Support\\\\Collection\\<int, array\\<int, int\\>\\> but returns Illuminate\\\\Support\\\\Collection\\<int, Illuminate\\\\Support\\\\Collection\\<int, int\\>\\>\\.$#"
+            count: 1
+            path: app/Member/FilterScope.php
+
+        -
+            message: "#^Parameter \\#1 \\.\\.\\.\\$parts of method App\\\\Member\\\\FilterScope\\:\\:combinations\\(\\) expects array\\<int, int\\>, array\\<int, array\\<int, int\\>\\> given\\.$#"
+            count: 1
+            path: app/Member/FilterScope.php