diff --git a/tests/Core/File/GetMemberPropertiesTest.inc b/tests/Core/File/GetMemberPropertiesTest.inc
index af52ff75df..8c87c64035 100644
--- a/tests/Core/File/GetMemberPropertiesTest.inc
+++ b/tests/Core/File/GetMemberPropertiesTest.inc
@@ -179,3 +179,12 @@ function_call( 'param', new class {
     /* testNestedMethodParam 2 */
     public function __construct( $open, $post_id ) {}
 }, 10, 2 );
+
+class PHP8Mixed {
+    /* testPHP8MixedTypeHint */
+    public static miXed $mixed;
+
+    /* testPHP8MixedTypeHintNullable */
+    // Intentional fatal error - nullability is not allowed with mixed, but that's not the concern of the method.
+    private ?mixed $nullableMixed;
+}
diff --git a/tests/Core/File/GetMemberPropertiesTest.php b/tests/Core/File/GetMemberPropertiesTest.php
index a4bff22133..3e8d164dcd 100644
--- a/tests/Core/File/GetMemberPropertiesTest.php
+++ b/tests/Core/File/GetMemberPropertiesTest.php
@@ -459,6 +459,26 @@ public function dataGetMemberProperties()
                     'nullable_type'   => false,
                 ],
             ],
+            [
+                '/* testPHP8MixedTypeHint */',
+                [
+                    'scope'           => 'public',
+                    'scope_specified' => true,
+                    'is_static'       => true,
+                    'type'            => 'miXed',
+                    'nullable_type'   => false,
+                ],
+            ],
+            [
+                '/* testPHP8MixedTypeHintNullable */',
+                [
+                    'scope'           => 'private',
+                    'scope_specified' => true,
+                    'is_static'       => false,
+                    'type'            => '?mixed',
+                    'nullable_type'   => true,
+                ],
+            ],
         ];
 
     }//end dataGetMemberProperties()