diff --git a/src/hgdaemon/ArcanistHgClientChannel.php b/src/hgdaemon/ArcanistHgClientChannel.php
--- a/src/hgdaemon/ArcanistHgClientChannel.php
+++ b/src/hgdaemon/ArcanistHgClientChannel.php
@@ -50,7 +50,7 @@
    * For a detailed description of the cmdserver protocol, see
    * @{class:ArcanistHgServerChannel}.
    *
-   * @param pair<string,string> $argv The <channel, data> pair to encode.
+   * @param array<string,string> $argv The <channel, data> pair to encode.
    * @return string Encoded string for transmission to the client.
    *
    * @task protocol
diff --git a/src/hgdaemon/ArcanistHgServerChannel.php b/src/hgdaemon/ArcanistHgServerChannel.php
--- a/src/hgdaemon/ArcanistHgServerChannel.php
+++ b/src/hgdaemon/ArcanistHgServerChannel.php
@@ -117,7 +117,7 @@
    *   array('o', '<data...>');
    *
    * @param string $data Bytes from the server.
-   * @return list<pair<string,string>> Zero or more complete messages.
+   * @return list<array<string,string>> Zero or more complete messages.
    *
    * @task protocol
    */
diff --git a/src/lint/linter/ArcanistScriptAndRegexLinter.php b/src/lint/linter/ArcanistScriptAndRegexLinter.php
--- a/src/lint/linter/ArcanistScriptAndRegexLinter.php
+++ b/src/lint/linter/ArcanistScriptAndRegexLinter.php
@@ -326,7 +326,7 @@
    *
    * @param dict $match Captured groups from regex.
    * @param string $path
-   * @return pair<int|null,int|null> Line and character of the message.
+   * @return array<int|null,int|null> Line and character of the message.
    *
    * @task parse
    */
diff --git a/src/parser/PhutilQueryStringParser.php b/src/parser/PhutilQueryStringParser.php
--- a/src/parser/PhutilQueryStringParser.php
+++ b/src/parser/PhutilQueryStringParser.php
@@ -69,7 +69,7 @@
    * applies array rules and returns a dictionary.
    *
    * @param   string                      $query_string Query string.
-   * @return  list<pair<string, string>>  List of parsed parameters.
+   * @return  list<array<string, string>>  List of parsed parameters.
    */
   public function parseQueryStringToPairList($query_string) {
     $list = array();
diff --git a/src/parser/xhpast/api/__tests__/XHPASTNodeTestCase.php b/src/parser/xhpast/api/__tests__/XHPASTNodeTestCase.php
--- a/src/parser/xhpast/api/__tests__/XHPASTNodeTestCase.php
+++ b/src/parser/xhpast/api/__tests__/XHPASTNodeTestCase.php
@@ -74,7 +74,7 @@
    * ```
    *
    * @param  string                 $file The path to the test file.
-   * @return pair<XHPASTTree, map>  The first element of the pair is the
+   * @return array<XHPASTTree, map> The first element of the pair is the
    *                                `XHPASTTree` contained within the test file.
    *                                The second element of the pair is the
    *                                "expect" data.
diff --git a/src/utils/utils.php b/src/utils/utils.php
--- a/src/utils/utils.php
+++ b/src/utils/utils.php
@@ -1726,7 +1726,7 @@
  *
  * @param scalar $key HTTP parameter key.
  * @param scalar $value HTTP parameter value.
- * @return pair<string, string> Key and value as strings.
+ * @return array<string, string> Key and value as strings.
  */
 function phutil_http_parameter_pair($key, $value) {
   try {