diff --git a/src/Illuminate/Validation/Validator.php b/src/Illuminate/Validation/Validator.php
index 6c034b4a3d2c..7a394f089567 100755
--- a/src/Illuminate/Validation/Validator.php
+++ b/src/Illuminate/Validation/Validator.php
@@ -1242,6 +1242,12 @@ public function setRules(array $rules)
      */
     public function appendRules(array $rules)
     {
+        $rules = (new Collection($rules))
+            ->map(function ($value) {
+                return is_string($value) ? explode('|', $value) : $value;
+            })
+            ->all();
+
         return $this->setRules(array_merge_recursive($this->getRulesWithoutPlaceholders(), $rules));
     }
 
diff --git a/tests/Validation/ValidationValidatorTest.php b/tests/Validation/ValidationValidatorTest.php
index 9b67edf553b2..74d067737f76 100755
--- a/tests/Validation/ValidationValidatorTest.php
+++ b/tests/Validation/ValidationValidatorTest.php
@@ -7407,6 +7407,11 @@ public function testParsingArrayKeysWithDot()
         $v = new Validator($trans, ['foo.bar' => 'valid'], []);
         $v->sometimes('foo\.bar', 'required', fn () => true);
         $this->assertFalse($v->fails());
+
+        $v = new Validator($trans, ['name' => 'ab'], ['name' => 'required']);
+        $v->appendRules(['name' => 'string']);
+        $v->appendRules(['name' => 'min:5|max:255']);
+        $this->assertTrue($v->fails());
     }
 
     public function testParsingArrayKeysWithDotWhenTestingExistence()