diff --git a/phpBB/phpbb/search/backend/fulltext_native.php b/phpBB/phpbb/search/backend/fulltext_native.php
index ca71ae8bae..ffdcbff3db 100644
--- a/phpBB/phpbb/search/backend/fulltext_native.php
+++ b/phpBB/phpbb/search/backend/fulltext_native.php
@@ -308,7 +308,11 @@ class fulltext_native extends base implements search_backend_interface
 		);
 
 		$keywords = preg_replace($match, $replace, $keywords);
-		$num_keywords = count(explode(' ', $keywords));
+
+		// Ensure a space exists before +, - and | to make the split and count work correctly
+		$countable_keywords = preg_replace('/(?<!\s)(\+|\-|\|)/', ' $1', $keywords);
+
+		$num_keywords = count(explode(' ', $countable_keywords));
 
 		// We limit the number of allowed keywords to minimize load on the database
 		if ($this->config['max_num_search_keywords'] && $num_keywords > $this->config['max_num_search_keywords'])
diff --git a/tests/search/native_test.php b/tests/search/native_test.php
index 234bfff47d..50f2119e7f 100644
--- a/tests/search/native_test.php
+++ b/tests/search/native_test.php
@@ -34,6 +34,10 @@ class phpbb_search_native_test extends phpbb_search_test_case
 		$language = new \phpbb\language\language(new \phpbb\language\language_file_loader($phpbb_root_path, $phpEx));
 		$user = $this->createMock('\phpbb\user');
 
+		$lang_loader = new \phpbb\language\language_file_loader($phpbb_root_path, $phpEx);
+		$lang = new \phpbb\language\language($lang_loader);
+		$user = new \phpbb\user($lang, '\phpbb\datetime');;
+
 		$this->db = $this->new_dbal();
 		$tools_factory = new \phpbb\db\tools\factory();
 		$this->db_tools = $tools_factory->get($this->new_doctrine_dbal());
@@ -41,6 +45,7 @@ class phpbb_search_native_test extends phpbb_search_test_case
 		$class = self::get_search_wrapper('\phpbb\search\backend\fulltext_native');
 		$config['fulltext_native_min_chars'] = 2;
 		$config['fulltext_native_max_chars'] = 14;
+		$config['max_num_search_keywords'] = 10;
 		$this->search = new $class($config, $this->db, $this->db_tools, $phpbb_dispatcher, $language, $user, SEARCH_RESULTS_TABLE, SEARCH_WORDLIST_TABLE, SEARCH_WORDMATCH_TABLE, $phpbb_root_path, $phpEx);
 	}
 
@@ -262,4 +267,78 @@ class phpbb_search_native_test extends phpbb_search_test_case
 		}
 		$this->assert_array_content_equals($common, $this->search->get_common_words());
 	}
+
+	public function data_split_keywords_max(): array
+	{
+		return [
+			'character count within limits separated by more spaces' => [
+				'foo    bar    baz    boo    far   faz    roo     rar    raz    zoo',
+				'all',
+				false,
+			],
+			'character count within limits separated by spaces' => [
+				'foo bar baz boo far faz roo rar raz zoo',
+				'all',
+				false,
+			],
+			'character count within limits separated by +, spaces after +' => [
+				'foo+ bar+ baz+ boo+ far+ faz+ roo+ rar+ raz+ zoo',
+				'all',
+				false,
+			],
+			'character count within limits separated by +, no spaces' => [
+				'foo+bar+baz+boo+far+faz+roo+rar+raz+zoo',
+				'all',
+				false,
+			],
+			'character count outside limits separated by +, no spaces' => [
+				'foo+bar+baz+boo+far+faz+roo+rar+raz+zoo+zar',
+				'all',
+				true,
+			],
+			'character count outside limits separated by + and spaces' => [
+				'foo +bar +baz +boo +far +faz +roo +rar +raz +zoo +zar',
+				'all',
+				true,
+			],
+			'character count outside limits separated by spaces' => [
+				'foo bar baz boo far faz roo rar raz zoo zar',
+				'all',
+				true,
+			],
+			'character count outside limits separated by -, no spaces' => [
+				'foo-bar-baz-boo-far-faz-roo-rar-raz-zoo-zar',
+				'all',
+				true,
+			],
+			'character count outside limits separated by - and spaces' => [
+				'foo -bar -baz -boo -far -faz -roo -rar -raz -zoo -zar',
+				'all',
+				true,
+			],
+			'character count outside limits separated by |, no spaces' => [
+				'foo|bar|baz|boo|far|faz|roo|rar|raz|zoo|zar',
+				'all',
+				true,
+			],
+			'character count outside limits separated by | and spaces' => [
+				'foo |bar |baz |boo |far |faz |roo |rar |raz |zoo |zar',
+				'all',
+				true,
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider data_split_keywords_max
+	 */
+	public function test_split_max_keywords($keywords, $terms, $expect_error)
+	{
+		if ($expect_error)
+		{
+			$this->setExpectedTriggerError(E_USER_NOTICE, 'MAX_NUM_SEARCH_KEYWORDS_REFINE');
+		}
+
+		$this->assertTrue($this->search->split_keywords($keywords, $terms));
+	}
 }